d100 interstices in the veins

for entering and exiting cities, mostly.

these are not the only part of the journey, but the inflection point:

1. sewer pipes full of bums
2. chevrons of cleared space around a vault door
3. reroll and add “...however it has all been cleared out and is shiny from constant use”
4. really long climb up/down to otherwise innocuous entrance, right next to thoroughfare
5. ropework crosses across deafening river 60ft below, deviant teens harass
6. people will actually try and recommend you use huge bats or something, this is a rude ploy, the actual path is being hidden by them 
7. use one of the hundred caves from that table in the book but there are d20 guards just waiting there
8. like the series of train cars in Snowpiercer, a literalized class distinction, everyone is fine with you travelling one direction only
9. some guy has set up a checkpoint alike TSA, claims royal authority
10. a metal and partially damaged ladder overhangs part of the city
11. bridges of junk form in the piss-river
12. a little-used trapdoor in a shop feeds directly into a cave system full of tight passes.
13. airlock-style thing that doesn’t work and no-one maintains
14. the city is actually dangerously close to a large number of cholerids who refuse to die. they’re behind a series of barred and curse-papered doors. they’re audible as you pass
15. a really, really long well, complete with drip-splashes
16. everyone just squirms through this crack into the lab from Resident Evil 4, but all the high-tech equipment is ruined and has graffiti over it, regenerators absent, hopefully
17. you have to actually complete a zelda-puzzle to get through this part. it’s dumb and easy and everyone says so but there’s some sort of ancient bargain or magic or tech that maintains it
18. zone is full of knife-wielding, screaming ghosts that are harmless
19. fata-morgana-style audio effect causes you to think that there’s actually a second city underneath the long, thin, and handhold-spotted bridge you must crawl over
20. people are playing a game with cutting off thumbs, there are multiple groups of travellers stopped to watch
21. cave-troll only lets you pass if you let him lick you. it is not sexual
22. there is an ongoing and fantastically expensive battle happening here, much alike the “bridge” sequence from Apocalypse Now. bc the most valuable thing to anyone involved is everyone’s flesh, it’s pretty much a free-for-all. that being said it’s not too hard to pass by without getting involved.
23. darkness is so intense that your light sources don’t work anyway, or only work 5’, there’s a endlesss amount of shells that crack underfoot
24. track left from a rolling boulder trap, always seems freshly sprung
25. something about the air around here makes your ears pop strongly, there’s a fizzling sound like hydrochloric acid dissolving earwax. certain parts of the caves require tremendous fortitude to push through as your body shakes violently, some sort of magnetic barrier going on
26. huge heaps of broken climbing equipment, surrounding a perfectly clean wall. climbing the wall seems like the easiest way into the city.
27. large part of the journey is over knife-like floor which shreds your boots
28. people regularly dig through ash-heaps which form like intense snow drifts, always covering the one funnel-like crawl out
29. impossible to tell if they’re living guards or statues
30. gnonmen are actively carving the exit here, it’s fresh
31. like the stairway to elatior in MOTBM-- you think you’re going down but halfway you get confused and end up coming up
32. abandoned mega-artillery surround some ancient battleground, they were powered by an energy source forgotten and extinct
33. slaves live in little houses at the bottom of sand pits, constantly maintaining the pits to prevent the encroaching sweating sandstone (from Koko Abe’s The Woman in the Dunes). someone will make you pay a toll
34. you have to climb through a series of ancient gearworks, and one that still works, it’s being run by a robot and doesn’t do anything
35. a million twisty tunnels all lead in the same direction, faux-maze
36. terribly clean marble hallway
37. there’s a tableaux of a frozen dead person, and an animal that tried to eat that person, and a person who tried to eat that animal, and a giant bug... it’s unclear if it’s someone’s art, but they’re all extremely contoured, there are some pieces chopped off
38. place was clearly once a public ampitheatre of some kind + dripping water, streamlets form passable tunnels
39. working modern elevator
40. the shrine past the bridge in Shadow of the Colossus, with the ramp, pool, ruined statues and altar
41. muzak-sounds drifting through a boring walk
42. drawbridge
43. reverse-drawbridge, i.e. they raise and lower the moat
44. ludicrously long drawbridge
45. seriously damaged drawbridge
46. remains of drawbridge over dried moat
47. the many ants here are impossible to catch
48. stairway stretched like a toddler drew it
49. enormously large stairs
50. two long metal prongs disrupt the tunnel in just a way where you can’t walk. have to crawl, seem to shift position over course of crawl. archers could stand at the end with great vantage, if they had enough light
51. it’s a breakdown made out of file cabinents, don’t describe them as “file cabinents”
52. a series of nets over an abyss, crawling across them makes your heart and stomach swim
53. very long series of propped-up cage doors, noisy like walking across chain-link fence
54. much larger and empty city surrounds the occupied one
55. ferry with hooded figure, it’s cliche
56. your path takes you over a series of peaks from which are visible other travellers on separate peaks but your paths never quite cross
57. a magma ferry provided by a huge, invulnerable, nonspeaking worm, travel is in the mouth. you do have to throw payment down its gullet.
58. shockingly powerful and brief squalls lambast an otherwise usual cave system
59. harlequin guards perform for you? 
60. you ALWAYS interrupt someone having sex when you come through here
61. ferry and drawbridge operators competing
62. long staircase
63. cambrimen-operated drawbridge
64. cambrimen-operated ferry
65. shaftway with a 1-inch wide staircase threaded inside, barely practical
66. mega cat haunts fissures, reaches in paw and tries to grab you
67. the opening to Aguirre, Wrath of God, underground
68. mouth-door with riddles tries to out-think locals
69. emerald city little door guard cliche
70. guard is also a skilled and passionate barber
71. rope-pass with blinding particulate matter
72. dead mouth-door
73. cave giant with bowl will raise/lower you and kills the poor and vulnerable
74. (stone) golf course with size-changing ferretmen out to hide in the holes and creep on you
75. this underground settlement is in the middle of an underground desert
76. you have to dive through a freezing sump to get here, people here are super willing to get naked to help you with hypothermia. they don’t consider it sexual
77. train-tracks suspended above an unnavigable river
78. locals insist the pass is safe, there are plenty of falling rocks, no one ever gets hit
79. they pull up a drawbridge to block the waterfall
80. tunnel rotates on a vertical/horizontal axis, crocodile man has the controls
81. salt path parts oozeroom
82. barrier from valley of unknown evils maintained by hex you must walk as a (linear) maze
83. linear maze-crawl, takes hours
84. sooty passageways in cave-reclaimed industrial building
85. tunnel steals fingernails, clumps come off in hand, it must also grow fingernails?
86. you have to wade through silty mud and watch out for quicksand
87. half-sunken crypt infested with very smart rats
88. the exit is also where everyone sleeps, as is custom
89. there’s a logbook you’re supposed to sign
90. carvings near entrance crudely depict pariah
91. reclaimed alkalion tunnel
92. running out of steam here… it’s just a normal tunnel
93. red snake painted on wall takes you the right way to the city, green snake takes you to a dangerous dead end. on the way back out, it switches. locals can’t keep it straight.
94. sherrif climbs out to meet you and accompanies you out of town. reroll
95. sword firmly stuck in stone, around next bend two swords stuck in stone, around next bend two axes, next bend there’s three sword blades and two axe blades sticking out of the stone
96. Amigara Fault tunnels
97. hairy tunnel
98.  ladders tied together in the void
99.  rocks sweat gas and make airless pools
100. tunnel is a literal “vein” with blood and everything. not edible