Underland 1 - Terrain types

So ive found a few blogs of late on a similar idea for super hostile terrain. I want to use such horrible places for my new underland setting in play and for under my islands in the Tenkar's Landing shared setting. Also handy for my Psychon setting. The underland is a hostile remnant land where ancient and prehuman remains have been hidden away and forgotten by surface folk. It is a post apocalypse dark fantasy setting that should be horrible. This post is about the basic terrain. Another will be on citadels. Another on dungeons, ruins and settlements. One on fantasy versions of my citadel generators. Ive foolishly sent my players there so will be pumping out more content.

Light in this setting is dim but present in most cases for at least night vision to function. The are great lights on the tops of some ruined citadels also used as navigation beacons. These artificial lights might be any colour or have colour tints. Some flicker or fade seasonally. Bioluminescant growths are common but surface human vision may struggle at times.

December 18 to jan 8 will in Adelaide with possibly poor net access but will spend time editing old works.

1d10 Quick Terrain
1 Ash plains - wasteland covered in loose ash or possibly compacted or sodden
2 Gravel and rubble possibly from crushed city or carried down by rivers
3 Mudflats - vast flats of viscous semi liquid muck like a swamp or bog
4 Natural structures like cliffs, caves, petrified forests
5 Ruined structures - remains of shattered citadels
6 Remnants of humans or mere look alike
7 Semi submerged and flooded with liquid
8 Volcanic debree - dormant volcanic vents, basalt plugs, fields of volcanic rock
9  Fungus Forest or biological zone from shrubby giant lichen to giant shroom forest
10 Exotic hazardous terrain -

1d100 Underland Terrain
1 Ash plain desert from some volcano or cataclysm or industry
2 Dust plain deposited from a past explosion or wind
3 Bone dust and fragments, near powdered with fragments and chunks from some ancient tragedy
4 Black soot from ancient fire or industry
5 Sand plain from some ancient beach or body of water
6 Salt plain with dunes from some dehydrated sea bottom
7 Sulphur plain of yellow powder from volcanic activity
8 Chemical wastes of toxic or corrosive dust
9 Dried and powdered algae dust plains
10 Dried plains of spore dust
11 Plains of gravel chunks worn down from larger rocks
12 Guano from bats or other creatures
13 Semi precious stones of low grade value but very attractive
14 Crystal shards often clear but other colours like red or blue or mixed
15 Ground down rubble from ancient ruins of past civilisation
16 Plains of tiny fossils mostly of ancient sea life
17 Seam of coal rubble with fossil chunks of carbonised wood and creatures
18 Chunks of rubble from ancient headstones and tablets cover plain
19 Chunks of  compressed ash from past volcanic activity, very lightweight
20 Mounds of twitching undead body parts
21 Mudflats bubbling up from below and oozing over terrain
22 Swamp with simple vegetation and fungi barely growing in dim light, smells of decay
23 Salt mash with stinking black mud covered in crust of salt
24 Colourful bacterial sludge seemingly dirty water with rainbow shimmering on surface but alive
25 Transparent slime mould growing rampantly over area
25 Glowing raft of luminescent fungal slime twitching and moving
26 Warm mud boiling up with geysers, steam and colourful calcium deposits and bacterial pools
27 Slow moving lava plain with huge rafts of black rock crust hot to touch and dangerous
28 Great lake of god flesh twitching, gibbering. Spawning crawling flapping mutant things
29 A liquid living lake of evil with skin on surface allowing passage, spasms at touch of good
30 A great raft of twitching ambulatory fungi, giving off spores and squeaks
31 A petrified forest with stone tree trunks and other mineralised ancient life
32 Canyons and eroded galleys, with caves and remnants of ancient creek beds
33 Great stone towers cover plain from ancient erosion
34 Mesas and buttes covered area with plenty of hiding places
35 Sinkhole filled landscape with trickles of water and natural wells, some hidden
36 Riddled with ancient mines with many hidden shafts, mounds of rubble and rubbish
37 Great stone monoliths naturally left behind by glacial or erosion, seemingly man made
38 Hills and cliffs riddled with caves, some huge spaces with waterways and great shafts
39 Plain of cooled lave covered in great slabs separated by several meters jump
40 Bizarre wind carved monoliths that whistle in the wind
41 Processional path lined with great statues of strange sphinxes or other mythic creatures
42 Great stone heads of old gods or prehumans, semi exposed from soil and embedded in cliffs
43 A great plain of stone megaliths in circles and processional routes, with great earth mounds
44 Huge graveyard with worn semi exposed graves, ruined mausoleums and crumbling tombs
45 A crumbling estate with manor, ruined walls, overgrown gardens and servants houses
46 Great ruined fort with battlements, crumbling gates and towers with remnants of ancient battle
47 Rubble of ancient city with remaining intact buildings and walls, possible degenerate residents
48 Ruins of villages and farmland with overgrown fields (probably with fungus)
49 Remnants of a old battlefield chocked with corpses, broken weapons, bones and feasting animals
50 Remains of a collapsed sprawling monument like a pyramid, citadel or other wonder
51 Blasted hills actually mounds of ancient cities with remnants of bricks from lost civilisation
52 Giant hexagonal stone steps and columns with caves probably formed by volcano or giant built
53 Semi submerged stones and pillars possibly cut or naturally formed with submerged tunnels
54 Algae covered cobblestones and huge stone slabs with submerged structures and caves
55 Garbage from ancient cities of flushed from distant cities of the surface
56 Ruins covered in growths of colossal fungus, sculptures and archways semi consumed by growths
57 Charred and burned rubble of some civilisation destroyed by volcano or great fire from heaven
58 Craters and scattered fragments of civilisation as if destroyed by great weapons of godlike power
59 Alien ruins of unfamiliar design and strange geometry with remains of huge inhuman skeletons
60 A once titanic organic structure with inhabitants, now dead and crumbling haunted ruin
61 Pure fresh water, crystal clear with albino cave fish and crustaceans of long extinct types
62 Dirty pools of contaminated water clouded with coloured soil, surrounded by rubble heaps
62 Salt water with crusted deposits on shore, higher buoyancy than normal sea water
63 Heated springs steaming and surrounded by calcium deposits with occasional geysers
64 Bodies of water with strange colours and shades from bacteria and minerals but drinkable
65 Pools of corrosives and acid, bubbling with vile vapours and strange colours
66 Bubbling pits of bitumen and highly flammable tar, possible animal remains of trapped victims
67 Pools of oil some bubbling with natural gas and toxic fumes
68 Hellscape of pits of burning oil and jets of flaming gas
69 Coloured warm water full of minerals and bacteria form great cloud like rafts of foam and calcium
70 Bubbling natural spring water with healing and rejuvenating properties
71 Steam covered plain of mud, geysers and hot spirings, shrouded in mist
72 Rivers of lava with bridges and land masses of basalt in between
73 Black stone domes, warm to touch, in some places collapsed into volcanic pits of fire
74 Great craters with strange coloured lakes some possibly alkali and corrosive, while others pure
74 Dark rocky flowing stone with vents of black sooty smoke pouring out, pits full of salamanders
75 Rough ground with strange vapours pouring from cracks causing visions or illness
76 Psychedelic wasteland of mist, coloured crystalline mounds and steam vents and strange pools
78 Black glass plain with glass citadels and castles remaining from the wizard wars apocalypse
79 A huge maze of volcanic rock where aerial predators swoop on those who try to climb walls
80 A grey plain of boulders and caves littered with bones and prehistoric art and graves
81 Giant shroom forest with great prehistoric lizards and giant bugs in a complex eco system
82 Great plateaus surrounded by mist supporting own strange eco systems from the distant past
83 A slime covered land of mould, lichen, gelatinous goop, oozes and other disgusting horrors
84 A great fungal mass all connected with other creatures living and growing amid its mass
85 A fungal plain of fungi which reacts to intruders with explosions, spore clouds and even screams
86 Fungi landscape where creatures converted to same breed of hostile fungus in fake ecology
87 A fungal land crawling with mushroom and toadstool folk swarming in strange rituals and spore clouds
88 A fungus forest densely populated by goblinoids and dark elves who live in giant mushroom houses
89 Great rafts of frothy slime where giant slugs and other invertebrates gather to drink and eat
90 A land of scrubby giant lichen, fungi, giant bugs and ant mounds, where huge ants tend landscape
91 A forest of giant crystals with occasional odd colours, magical fields and crystaline creatures
92 Magical aurora blasted landscape of rubble, craters and ruins, visitors are affected by weird magic
93 Animated terrain of rubble, garbage and piles of rusty cogs where golem things spontaneously form
94 Fused bone landscape made by elder necromancers in bone towers, crawling with undead
95 Black basalt towers of serpent and lizard men surrounded by fungus jungle and albino dinosaurs
96 A land of stony pillars and caves covered in cobweb homes of spiders, some in swarms or gigantic
97 Covered in spasming twitching worms, vary from region may include maggots, leeches or earthworms
98 Land of people or other creatures in stasis standing or in heaps for some forgotten purpose
99 Pits of larvae with human faces tormented by devils in this region with gates to hell and volcanoes
100 Frozen mountains of ice riddled with caves, some hollowed by volcanic activity

some others...
lakes of blood probably from blood sucker dung mixing with water in rotting mess