1d100 - Secret Doors

1. An empty doorframe that functions like a normal door when one's eyes are closed.
2. Two empty sconces set in a wall. When candles are set and lit, their shadows converge to form a door.
3. One small, dusty vial with pink liquid inside. When drizzled out, the liquid forms a temporary archway before reverting.
4. Bamboo grows out of a vase. When sliced, a door sprouts from the cutting.
5. Origami figurines that unfold to reveal full-sized doorways.
6. Thick dust needs to be swept away to reveal the door underneath.
7. The gate only appears when all of the light sources in the room have been extinguished.
8. A trapdoor is built into the bottom of the statue itself.
9. Motes of color float about the room and need to be returned to their jars before their light forms the door.
10. It's the natural stone wall that repairs itself, regrowing over the door. It needs to be shattered every time.
11. The room is full of comfortable beds. Those who rest their head will rise and sleepwalk through the invisible door.
12. Only when moonlight filters in through the skylight does the door appear.
13. Grooved channels stem from the dais towards the stone slab door. Blood must flow before it will move.
14. Once water fills the bowl of the birdbath, a door appears at the bottom of that stone basin.
15. No door will appear in the small room until all one-hundred candles are lit.
16. All four walls of a room are made of doors. The real door will not appear in the floor until every false door is ajar.
17. The offset door in the wall is a fake - the real door is invisible beside it in the center of the wall.
18. The wall remains blank until someone offers food to the massive brass dog statues.
19. Nestled inside the neck of a fat vase, the door is clearly visible though strangely distorted.
20. The door to the thief's bazaar will not reveal itself until the captain of the guard is asleep in his bed.
21. Twelve doors in a circle - which one is currently visible depends on the hour of the day.
22. It's not until someone asks nicely that the door will reveal itself.
23. Where the door leads depends on whether the opener knocked or not.
24. Atop a small table is an hourglass. It's a one-hour timer that alerts a nearby creature, but at the end a door materializes.
25. The door works just  fine, if you find the right angle to look at it.
26. Every time you open the door, there's a smaller door nestled inside.
27. The giant mirror hides a door behind it, but the real door is the mirror itself.
28. Stones have been set out in a strange circle. The creature conjured by them will bargain to create the door.
29. Dozens of tiny jars on strings. Inside are tiny items that, when freed, return to their normal size. The door jar is hidden.
30. A small fireplace houses a crackling fire. There's a door is in the smoke flute.
31. The statue of a muse hides a secret door that will only be revealed when music is played.
32. A dirt floor hides a barely-hidden trapdoor, and a shallow grave where a corpse is curled up with the key.
33. Two talking stone heads argue over the location of the door. It appears between them when they agree.
34. Strange flowers bloom throughout the room. Inhaling their scent induces hallucinations, wherein the door is found.
35. The door is hidden forty feet off the ground with nary a handhold or ledge to be seen.
36. The greedy monster that guards the treasure will reveal a hidden door if bought out with silver.
37. Until incense is set to burn, the door to the dream-land will never be revealed.
38. An armored wagon carries the door about, well-defended.
39. A column of stone rises up in front of the door, preventing it from opening.
40. A tree has grown up around the door, almost hiding it from view entirely and making entry rather tricky.
41. Two dozen ornate door knobs are scattered on the ground, and none of them seem to match the non-functional door.
42. Sitting atop a lectern is an imposing tome written in a strange language. If opened, it begins to tear open a door in reality.
43. A staircase appears to lead to nowhere. Climbing it, however, is more productive.
44. Goblins tore the door from its hinges and turned it into a table. It still functions in a manner that defies comprehension.
45. A huge brass brazier needs only be filled and lit to reveal a door in the smoke.
46. A set of marked graves have been disturbed. The one that is dug up is now a gateway.
47. The painting contains a few strange hints about the door hidden elsewhere in the dungeon.
48. There's a door hidden in the back of the larder, behind molding and rotten food.
49. Set in a wall of black granite, the door only appears when brightly illuminated. Specks of it can be seen in dim light.
50. A sadistic genie bound to the room threatens to kill anyone who wishes for him to reveal the door he guards.
51. The room is flooded with murky water. At least two trapdoors are hidden underneath, concealing flooded passages.
52. An open ceiling allows the stars to dictate when the door is visible.
53. Dead corpses are piled in a pit, ready to be consumed in a funeral pyre. A hidden door in the pit allowed a few to escape.
54. A room of bodies in gibbets and dangling in nooses. A hand of glory is required to open the hidden way.
55. Emerald water and venomous eels create an odd pond. A door can barely be seen inside, tangled in moss and seaweed.
56. A spectre haunts the halls, and a key for a secret door hangs from its neck.
57. Eyeholes, arrow-slits and hollow walls indicate many secret passages. The doors can be opened by pressing loose stones.
58. False bookcases lead to a hidden room. A secret door in that room can be found by carefully examining book titles.
59. A huge bas relief depicts an ancient worship scene. Finding missing pieces reveals a hidden passageway.
60. Only those who are fully rested in the natural hot springs can see the door with their eyes half-lidded.
61. Odd birds roost in the dungeon. Their mating songs can conjure a door of sound into existence.
62. A swift-running stream runs through the dungeon, and beneath the small waterfall at its source is a ceramic door.
63. Hidden behind a misplaced boot is a tiny, tiny door. A small village lives in the walls, here.
64. There exists a door that can only be seen by those who have lost their mind. It leads to a calm place.
65. A black chalice turns water into wine. When consumed, the imbiber can step through shadows to another realm.
66. A set of mirrors must be adjusted so that the light of two braziers meet, conjuring a door of pure energy.
67. Nestled deep inside the mouth of a horrendous statue is a door to a secret chamber.
68. Juicy fruit on a dead tree contain tiny keys. In the hollow of that tree is a tall, slim, locked door.
69. A cracked cauldron sits on a rug atop a trapdoor. The children who are to be eaten are trapped in that chamber.
70. Deep in the forest, a nymph whispers that there is a door in the stump of an ancient tree. It must be felled to reach it.
71. A door atop a tower can only be seen on stormy nights, and the nearby village fears the creature that goes through it.
72. The nervous cleric has found a door to a cursed catacomb, and hidden it away with rich tapestries.
73. Prisms have been set up, dangling from chains in the ceiling. When lanterns are used, they reveal doors in the walls.
74. A charred room hides two doors, obscured by rubble, ash and scorch marks. 
75. A monstrous cyclops has hidden his door so that only those with a single eye can see it.
76. Frogs sit on their lilypads, croaking out a queer song. A trapdoor can be found if one chases them off and moves the pads.
77. A stained glass window displays a touching scene, and hides secret panels that open a hidden door.
78. The door is made of ice; so is wall. Strange scrapes and a small pool of slush help draw the eye.
79. Odd brickwork hints at a door that has been paved over. Something was sealed inside.
80. A glaring face has a sign that demands payment. Those who offer something of worth will be devoured by the doorway.
81. Liquid fire flows like a river. Brass bowls are used to carry it to a shrine where it is used to unveil the gate.
82. Covered in leaves and old growth, the door has almost returned to nature, but it still works fine.
83. In the headquarters of a paladin order, there exists a door beneath a large altar that reveals an older church hidden beneath.
84. The blood of a ferocious tiger conjures a portal when it is spilled.
85. In the hall of broken daggers, a door is hidden beneath the steel shards.
86. Lava has flooded the lower chambers, and a sturdy door of obsidian is now fully submerged.
87. The Worm King's mass hides a secret compartment. The key inside opens the ruby door.
88. The living granite statues will not move without the command scepter. The largest of them sits against a strange door.
89. Five doors are spaced strangely in a circular room, and the floor hints at a sixth that has no room to exist.
90. A moving wall threatens to crush the party, but behind it is a maintenance door.
91. The dusty, dry air is painful to breathe, and only those dying of dehydration can see the odd ruby door in this room.
92. A small passageway in the ceiling is difficult to spot, unless you are staring up out of the pitfall trap.
93. The floor contains a strange mechanism - strength and patience are required to move the huge gear and unveil the door.
94. Empty torch sconces need only be filled to reveal the door.
95. A pit, filled with rusty spikes and shin-deep stale water. A trapdoor rests at the bottom, obscured by grime.
96. The door is inside of a creature's stomach.
97. The acid flow is dangerous as it drips from the ceiling and forms hazardous pools, but in that deadly room is a golden door.
98. A devil guards a false artifact. He has disguised the door to the true treasure as a latrine.
99. Ornate curtains span the walls here. When those are pulled aside, a secret door leads to a filthy chamber.
100. Housed in a small box is a tiny brass key. Any door opened with this key in the lock will open to somewhere... Else.