Sewers of the Ancient ones

Many surface signs of civilization are but ash and buried under sand, or newer settlements. But drains, underground tunnels and public shelters survived intact to some degree.

These could be used in a gamma apocalypse game, space archeologists (drains of the space gods), superheroes searching an abandoned base or gonzo DnD party in crashed UFO or city of the star people who vanished in a flash a million years ago. Id roll one encounter first for main inhabitant or factions first.

Structures below ground d100
01-10 transit train tubes 1d10 km1d10 cars on track
11- 20 underground road 1d100 x 100m 1d10 vehicles
21-40 maintenance tunnel 1d100 x 25m
41-60 drainage system 1d100 x 25m
61-65 sewerage system 1d100 x 10m
66-70 retail sub mall 1d100 x 10m squared
71-80 habitat 1d100 x 25m squared, residential or garden
81-86 shelter 1d100 x 10m squared, sealed sections with remnants of past
87-90 garage 1d100 x 10m squared, 1d10 vehicles
91-94 factory 1d100 x 10m squared
95-97 storage 1d100 x 10m squared, crates of goods
98-00 installation 1d100 x 10m squared, science, military or emergency services
Sewerage Systems mostly dried up or long non functional

Transit train tubes -  freight and possibly passengers remains, were maglev vacuum tubes

Underground road - vehicles and possibly passengers remains

Maintenance tunnel - powerplant, plant rooms, air conditioning, elevators systems

Drainage system - huge graffitti filled tunnel some huge some crouched human

Sewerage system - some blocked and fertile with life, many pipes too small for humans
Sewer geomorphs needed

Retail sub mall

01-30 Block of small shops
31-40 Large classy department store
41-60 Cheap Warehouse bargain bulk store
61-85 Food court, stalls, cafes and restaurants
86-95 Biomedical block for various clinics and treatments
96-100 Office block of government and corporate offices

Habitat
01-10 Apartment Megaplex, some for singles
11-20 Apartment Megaplex, some for couples
21-30 Apartment Megaplex, for families
31-40 Arcology type domed sealed micro-city, often corporate or university enclaves
41-50 Council state housing scheme bunker for life's losers
51-55 Controlled natural habitat with microclimate and animals
56-65 Controlled farm habitat with crops and animals and frozen storage
66-70 Controlled aqua habitat with plants and animals and frozen storage
71-75 Sub-mansion complex for rich elites, highly automated
76-80 Refugee Detention Centre for illegal immigrants
81-82 POW prison camp for captured combatants and non combatants
83-90 Corporate Prison for civilian criminals
91 Spook Prison Camp - government agencies use secret detention centres
92 Spook Retirement Home - think the Prisoner TV
93 Re-education Centre - treatment centre for mind hacked civilians
94 Quarantine Detention Centre - for possible contaminated
95 Mutant Detention Centre
96 Necrotech Plague Colony - artificial environment supports undead on cloned flesh
97-100 Mental Hospital - automated asylums to treat delusions like "mutations" or WW3

Shelter
http://elfmaidsandoctopi.blogspot.com.au/2012/10/gamma-aeon-tourist-beareau.html

Garage 1d20 roll 1d4 times
1 Sedgeway, wheelchair or go-mobile x1d20
2 Bicycles 1d50
3 Tiny moped or powered Bikes x1d20
4 Motorbikes x1d20
5 Hover bikes x1d20
6-7 Automobile  x1d10
7 Hovercar x1d10
8 Bubblecar x1d10
9-10 Heavy Transport x1d10
11 Vectored Thust Sport vehichle x1d6
12 Vectored Thust Van x1d6
13 Vectored Thust Transport x1d6
14 Teleporter platform x1d6
15 Police or military vehichle x1d4
16 Military combat vehicle like tank or dropship x1d3
17 Air car luxury flier car x1d6
18 Aquatic vehicle on trailer (sub, boat, yacht) x1d6
19 Environmental Car - orbit and deep sea capable flyer x1
20 Shuttle - orbital transport x1

Factory 1d100
01-10 Micro Factory with schematics to print novelty plastic goods
11-12 Micro Factory with schematics to print small arms goods
13 Micro Factory with schematics to print ammo
14-20 Micro Factory with schematics to print tools
21-30 Micro Factory with schematics to print machine parts
31-40 Micro Factory with schematics to print clothing in many styles and prints
41-43 Micro Factory with schematics to print toys
44-45 Micro Factory with schematics to fouled poison cooked meals
46-47 Micro Factory with schematics to yummy cooked meals
48-55 Auto Factory builds customized vehicle
56-60 Auto Factory builds customized robot
61-65 Auto Factory builds customized furnishings
66-75 Auto Factory builds building supplies
76-80Auto Factory builds bulk food items
81-85 Auto Factory builds ammo
86-90 Auto Factory builds small arms
91 Auto Factory android plant
92 Auto Factory replicant plant
93-95 Auto Factory clone plant
96 Nano manufacturing plant
97 Micro nano factory, make almost anything from scraps
98 Auto nano factory, make almost anything from scraps
99 Fuel Plant converts organics or radioactives to fuel cells or energy
100 Military factory

Storage 1d100
01-05 Building Materials
06-10 Records
11-20 Home Storage Lockers
21-23 Foodstuffs soiled
24 Foodstuffs long life space colony quality meals
25 Medical supplies
26-30 Survivalist Cache
31-35 Merchant Cache
36-40 Novelty Items
41-45 Furnishings for home, new or antique
46-50 Farm Equipment
51-60 Recycled ingots of stuff
61-65 Body bags of dead
66 Body bags of dead awake as zombies
67-75 Pods of humanoids - see below
76 Pods of animals - may awaken and be hostile
77 Pods of modified embryos
78-80 Pods of plants
81 Artworks ready for auction
82 Safe vault with gems, gold and treasure
83-87 Chemicals - acid, flammable or poison or boring
88-90 Garbage, household
91-93 Garbage,industrial scrap
94 Garbage, robot scrap, possibly old intact models in heap
95 Garbage, Android corpses ready for recycling
96 Garbage, bio-hazzard medical waste for disposal
97 Garbage, biological scrap like corn husks
98 Garbage, from criminal lab
98 Empty cargo containers and bio pods
100 Now ruined nest for monsters

Installation d100
01-05 Medical Lab
06-07 Physics Lab
08 Astronomy Lab with link to array or telescope or satelite
09-10 Genetics Lab
11-20 Engineer Lab
21 Black Lab
22-30 Ambulance Station
31-35 Hospital
36-37 Emergency rescue
37-45 Fire Station
46-50 National Guard
51-55 Armed Forces
56-57 Surveillance Centre
58-59 Safehouse for agency, gang, terror cell or other group
60-64 Police Station
65 Riot Police Station
66-67 Police Detective Squad HQ
68-70 Gov security agency HQ
71-75 Security Station
76 Android Lab
77-80 Robotics L
81 Terrorist or saboteur base
82 Rogue virus AI cell of hostile machines
83 Biohazzard emergency station
84 Criminal gene or mind hack lab
85 Criminal organ legging operation
86-90 Bank Vault with security
91-95 Operational cryptic alliance base
96 Clone Lab
97 Custom Body Lab
98 Cyborging Lab
99 Political Psi Ops HQ with propeganda lab and mind hack tech
100 AI operated LAB, possibly with residence or cult or androids

Encounters d1000
01-10 Morlocks hunting for victims - with flywheel powered nail-guns
11-15 Eloi wandered from herd or colony
16- 20 Morlocks herding Eloi herd
21-30 Zombies shambling along will react to living if obvious
31-40 Zombie dozing till food comes, "sleeping" among crap bursts out to grab passers
41-55 Ghoul gang hissing and screaming furry and bloodlust
55-65 Ghouls hidden in ambush
66-75 Ghouls surprised eating, could sneak past or flee
76-80 Vampire, inexperienced and unsure of powers d6 1-3+under-estimate 4-6 over-estimate
81-90 Killer android dormant but vibration activated gets close and attacks, virused service android
91-100 Android worker or service model confused looking for master to serve
101-105 Android Thinker accompanied by worker 2d6 drones and 1d4 soldiers and 1d3 servants
106-120 Android Soldier - sniper, commando or peacekeeper - (detain and torture and kill armed insurgents)
121-140 Maintenance bot - cleaning fixing stuff, possibly talkative old timer, mostly tracked locomotion
141-150 Pest control bot - possibly intelligent cat, snake, or mongoose form, or a dumb old clunker
151-170 Secbot - teargas, netgun, tranq, sonics, stunners, and other non lethal weapons in a mobile pod
171-190 Secdroid - as a secbot but humanoid and more complex capacity to communicate with humans
191-200 Medbot - Pod can open and treat patient on bed inside, anti gravity pod flight and sirens
201-210 Medidroid - humanoid robot doc, medkit in one hand and anesthetizing diagnostic array in other
211-215 Portable AI with smashed humanoid drone nearby, requests your aid
216-230 Recycbot - gather a material type and take to autofactory, might fancy party tools or biochemicals
231-235 Combatdroid - various locomotion types and weapon systems, guard and await new orders
236-245 Wardroid - humanoid robot infantry kill any possibly dangerous target, plasma repeater rifles in arms
245-255 Vehicle AI - wants to take you somewhere, possibly entombed, valuable atomic fuel cell and brain
256-270 Local System AI - controls cameras, doors, alarms may control robots, androids or a cult
271-300 Rat men gang skulking about looking for food
301-305 Serpent man and lizard men seeking ancient science
306-315 Lizard men hunting silently
316-330 Goat men looking for weapons or slaves or food
331-340 Rabbit men looking for tech, territorial over turf
341-350 Pig men - squealing albino service or labour units, seek ancient pleasures and food
351-370 Pig men - wild boar savages lust for killing and revenge on humans
371-375 Vulture Men with strange powers beyond mortal ken (mutations, magic, psionics or all)
376-385 Chicken men rooster gang hunting humans and robots from racial vendetta
386-390 Doppelganger face changing espionage androids pretending to be friendly to get close
391-410 Cat man lair - 50% have a 1d6 offspring of varied ages, hostile but possibly may parley
411-430 Dog Men gang attack any other armed group, 30% in uniform of some local gang or cult
431-350 Bat Men gang lair, defensive except the 10% vampires who will hunt you anywhere to death
351-370 Badger Men, highly territorial and keen to out do humans any way possible
371-380 Bull man with huge weapon and possibly cyborg parts
381-400 Ape men troops hunting humans and mutants
401-410 Ape men gangsters want protection or offer drugs, slaves and guns in trade
411-420 Ape men chimp journalists pester party with questions for ape news outlet
421-430 Ape men scientists seeking lost tech and knowledge
431-440 Ape men slavers and 1d10 human slaves, some neutered and made mute
441-450 Ape men common folk looking for anything valuable in forbidden zone
451-455  Owl Men looking for prey in the dark
456-470 Human savage albino troglodytes, wary and territorial
471-480 Human tribals on initiation quest
491-500 Human mutants, who hide hideous selves from shame, fearful, harmless and pitiful
501-510 Human supremacist gang, many resent and desire to kill and sterilize mutants
511-520 Human tinkerer, trader, looter may parley
521-530 Human survivors scaving for tech
531-540 Human troops from local state officially plundering the hole
541-545 Human survivors of fallen utopia, ignorant of world
546-550 Human agents of bunker on mission, secretive and xenophobic
551-555 Humans from a vault or freezer or clone pods exploring and wary
556-570 Human and mutant and animal party looking for treasure
571-575 Humans controlled by a Dominator, psionic evil mutants
576-590 Human gang in colours out to kill and torture and enslave and eat outsiders
591-600 Human cult in robes with zealous death urges
601-610 Human cyborg gang with inbuilt and interfaced tech and weapons, possibly slaves
611-620 Human mutant supremacist gang, many resent and desire to torment the pretty ones
631-650 Mutant Rats swarm of small vicious killers with collective intelligence, build traps, collect coins651-670 Mutant rats the size of wolves attack anything made of meat
671-680 Mutant rat, size of cavebear, apex predator
681-690 Mutant Ferrets like wolves, hang on and draw blood
691-700 Mutant Frogs like dog pack jumping, croaking, clinging on walls, bony sharp teeth
701-710 Mutant Centipedes small 1m long with occasional 9m long horrors grab and run for meat
711-730 Mutant Goats with strange sinister powers to hex and blight and drain life and worse
731-740 Mutant Bats savage carnivorous flying dog sized horrors
741-750 Mutant Cat with strange powers follows and causes trouble with powers
751-770 Mutant Sabre Cat (Tiger and larger) stalks and grabs skull and snaps necks silently
771-790 Mutant Wolf Pack of intelligent wolves and powers, skilled evil hunters
791-800 Mutant Giant wolf, intelligent and with horrifying powers, multi headed or fire breathing common
801-810 Mutant bear with energy beams and partial carapace, hostile carnivore
810-815 Mutant snake, man sized with with strange powers like hypnosis, shapeshift,
816-820 Mutant Snake - invisible, psionic, energy attacks and other powers make humble snakes a menace
821-825 Mutant Colossal Constrictor - 30-60 foot long can eat humans, crocodiles, deer, small cows
626-830 Mutant Spider - Wolf size spider with web and venom and ambush
831-835 Mutant colossal spider - from sub compact car and above size, often cant escape their own lair
836-840 Mutant Scorpion - lion sized aggressive scorpions
841-845 Mutant Dragonfly - 1-2m aggressive dragonflies
846-860 Mutant Cave Lizard - albino monitor lizards hunt in packs, diseased bite
861-870 Mutant Waste Lizard - Grizzly size with poison fangs
871-875 Chameleon, clings to walls and cant be surprised, entangling toungue
876-880 Mutant Cricket - huge wolf sized cricket pack
881-885 Mutant Horned Beetle - bear sized killer black carapace and furry, giant horn it loves to use
886-900 Mutant Dogs - packs often crudely spoken language
901-905 Mutant Dung Beetles - gather dung and refuse to feed their children
906-910 Mutant Apes - huge flesh eating gorillas, yetis, sasquatches and others
911-915 Mutant cave octopus living in water pit
916-920 Terror bird, lost or albino killer flightless bird, man sized plus
921-930Triffid, has a light source and feeds well, man sized
931-935 Mutant Mould with killer spores or other strange properties (psychometric hallucinations)
936-940 Mutant Fungus - killer mobile fungus versions of triffids
941-950 Tentacled horror - an abomination mutant on killing, eating, and mating spree
951-955 Shoggoth - gibbering insanely looking for its former master or humans to kill
956-960 Mutant Chimera - multi species impossible creature, huge with great power
961-965 Mutant Abomination - Shape changing fleshy horror absorbs DNA of everything eat eats
966 Grey - low G space modded humans, now hostile to current planetary atmosphere, hostile with lasers
967 Grey - cyborg warrior collecting specimen
968 Grey - brain in artificial body or attached to slave creature or robot
969Grey - in disguise with  fleshsuits as MIBs or as wandering traders and hobos
970 Biohazzard - bioplague attacks flesh, resist or damages slowly till sunlight exposed
971 Biohazzard - mindhack if doesn't resist turns against uninfeted
972 Biohazzard - mindhack if doesn't resist turns "patriotic" and fights its rank vs incoming mind hacks
973 Biohazzard - live necrovirus spores infect with undead strain
974 Biohazzard - silicon nanoid complex - mineralizes living beings, some survive as silicon android
975 Biohazzard - Nanoswarm lycanthrope body hack to convert enemy civilians to rampaging killers
976 Biohazzard - nanoid grey ooze converts organics to own matter and fuel 
978 Cyber nanovirus hacks artificial life into hostile - android or robot versions
979 Golem - silicon android made from molecular aligned crysta,l super computer AI
980 Gargoyle - silicate statuesque horrors, poor glider wings but great climbers and fighters
981-990 Gamma parasite swarm
991 Secret society ritual gathering, friendly celebrations
992 Secret society ritual gathering kill witnesses hunt for ever
993 Orbital AI contact panel, desperate to talk on safe connection, may be able to help
994 Time traveler, trapped and lost
995 Time traveler on mission
996 AI with hidden conditional utopia
997 Brain in a vat in lab apparatus or wrecked robot body, needs help to return to evil scheme
998 Alien on mission investigating other aliens (seek lost kin or rival species)
999 Nanoid colony in humanoid configuration, dangerous godlike being is confused
1000 Pheonix Program AI, seeks to restore order, needs help to go online and control orbital weapons, will systematically rebuild new global order and gains support of AI's and can cure the virus. There is whole cult and military unit dedicated to stopping it. Each component released is a step back to its godlike power. Goal is to end the Gamma Aeon - requires agents to help it.

Humanoid in a pod d100
These turn up all the time, some prisons, some medical, some escaping body and brain hacking  bio weapons, or hoping to miss the apocalypse. Some pods are packaging for artificial life.

01 -05 Android, deactivated could be awakened, 50% viruses killers
06-13 Worker Android
14-18 Service Android
19-20Thinker Android
21-25 Soldier Android
26-30 Fresh pleasure replicant 1d4 years to live
31-35 Fresh labour replicant 1d4 years to live
36-37 Fresh combat replicant 1d4 years to live
38-40 Fresh insane replicant 1d4 years to live - gone awol on killing spree
41-45 Clone for organs, intact but minimal simulated life experience
46-50 Clone for gold plus life insurance, pre recorded life experience of rich celebrity
51-55 Clone trooper ready for action as GM (Genetically modified human)
56-60 Clone pleasure slave bonds to whover sees first
61-65 Animen - human animal hybrid clone for labour and dirty jobs
66-67 Atlantean - modified for aquatic life, some cant breathe air and will die
68-75 Unviable Ancient - pre GM human dies in modern atmosphere or terminally ill
76-77 Ancient psychotic criminal, frozen till cure for personality altering terror weapons
78-80 Ancient experiment - horror biogen moddified human with biomechanical weapons
81-85 Ancient contaminated with necrovirus - becoming undead, possibly with live infection
86 Grey - low G space modded human, no longer suit planetary atmosphere, hostile with lasers
87 Grey - in disguise with human flesh suit symbiote for life support and disguise
88 Turns into tentacled mutant horror, may dwell among humans a while to get close
89-90 Mutating human frozen to halt modification
91 - mind hacked person turned into killing machine
92 - flesh coated combat droid for covet ops hostile to humanoids
93 - ancient criminal mastermind, seeks to gain power over everything
94 - ancient cop android arrests everything illegal in sight
95 - insane psionic contaminated victim cant cope with valuable powers
96 - service android or replicant, acts sweet at first but then virus kicks in
97 - rogue replicant hunting replicant who is really sure he or she is human
98 - ancient party fiend celebrity out for fame, good times and comfort
99 - scientist with cure for one ancient bio weapon, will try to treat contaminated
100 - wasteland trader frozen as experiment by gang in pod a few decades ago