Here's my entry, totally not balanced or playtested in any way! For a party of level 3-ish...
Treasure Vault of the Corux
This adventure takes place after some recent ground tremors. I leave the overland stuff and the getting to the site to the DM. Whispers start going on around town that somebody has found an interesting archaeological find, something about a "Corux tomb", whatever that is....
“Y'all dun heard they dug up some kinda fancy tomb round here!? I reckon those types had some neat stuff buried with em! Always good pickens so long as nobody dun been messin' with nothin' Prolly some booby traps though... gotta outsmart that stuff!”
“The Corux... names I've not heard in some time. Heavenly beings they were – legend holds that they stowed away the secret to immortality with the few that couldn't be brought along back to paradise with them before they left our realm for good”
“Careful finding your fortunes 'round these parts. My cousin is a guardsman, and the way he tells it, there's these weird black monsters crawling up from the ground. Might have had to do with that last earthquake he had, but I ain't exactly no geologist or nothin'”
“My brother Billy had a bad dream last night and wet his pants. He says a little demon baby trapped in a hand wanted his help. Scared him real bad! Scared of a baby! Ha ha! Billy is a pee-pants!”
Roll 1d6 for each hour spent here; on a 1, there is a random encounter with a Chaos Hatchling (a creature with a random, unnatural form). Chaos Hatchlings have darkvision out to 60', and understand no languages. Assume they add no modifiers to skill checks, ability checks, or saving throws. Examples of these can be found in Areas 13, 16, 17,19 or 20, or you can use this template:
Chaos Hatchling – AC 12, HP 40, weak to radiant, bite +5 melee (2d6 + 2 piercing) or 2x scything attacks +5 melee (1d6 + 2 slashing) or poison spit +5 15' ranged/1 target (DC 12 CON save or poisoned for 1 minute)
1 - The columns supporting the vaulted ceiling of this white marble hall are carved to resemble pairs of dancing animal-headed people; two of each owl-heads, fox-heads, goat-heads, tiger-heads and cobra-heads square off as partners, and when not looked-at, change poses randomly in dance until looked at again. Marble bricks are scattered across the ground in front of the 10' tall hole in the east wall, having been burst outward from the other side.
2 - The water pool that dominates this room is only an inch deep, but looks as though it stretches downward into oblivion. Thirty feet above, a lattice-caged bridge bisects the room, forming a tunnel between two similarly caged spheroid rooms cut into the opposite walls. From the underside, the rooms and bridge are carved with a scene of a playful battle between two groups of cherubic wizards.
Treasure: Embedded gemstone flecks (100gp total) add a colorful shimmer to the spell effects in the carving. Prying them all out takes an hour, and the ability to reach them 30' up.
Encounter: From the lattice caged areas above, a solitary figure robed in shadowy vines takes potshots at those below using a blowgun (see Area 8). Attacking this creature requires a successful attack against an of AC 18 – hitting it three times (no matter the damage) causes it to retreat from sight.
Boon: If a creature lies down in the pool and washes themselves, they recover one hit point for each minute spent bathing.
Trap: If a creature bathes in the pool more than once per day, the depth of the water drops away into infinity, and a vortex forms to pull all bathers down to a watery death (DC 12 to fight the current and escape the pool).
3 - The twelve marble statues here are paired figures with animal heads, matching those in Area 1, except they all war a scornful look and their eyes move to follow creatures moving down the hall. The second pair are pig-headed people not found in Area 1; behind the male, a secret door can be opened by pressing two buttons in the statue's nose (DC 15 to spot).
Trap: If anyone tries to pass between the cobra-headed pair of statues (the northernmost pair), they can notice a subtle movement of the mouths (DC 12). Creatures that see this are allowed a DEX save (DC 12) to avoid a venomous spit attacks from each of the pair (+5 to hit, 2d6 poison each).
Exits: The door to Area 4 is a bronze disk with a valve wheel in the middle - opening it requires a combined STR of 30; only two individuals can attempt simultaneously. The room beyond is pressurized, hissing when opened.
4 - The mahogany statue in the middle of this room depicts a pair of dryads dancing naked around a maypole. Living garland strings from the top of the maypole to the walls, where they grow further into knotted tangles of flowering vines, covering almost every surface in the room. The delicate flowers on the vines crumble at the slightest touch.
Treasure: a DC 15 Nature check (or equivalent) identifies some of the plant species as having been extinct for thousands of years – 50gp worth of rare seeds can be collected for each half-hour spent sifting through the detritus (max 250gp worth).
Trap: Each half-hour spent here requires a CON saving throw (DC 10); failure means the player has contracted a formally-extinct disease (details left to DM, highly visible symptoms, not easily treated, rightfully shunned by society).
5 - A 20' tall forearm of volcanic glass, capped with a loosely-clenched fist, appears as though it has burst upward through the floor. Around its base, a roiling pool of magma churns from within a sinkhole-like depression.
Trap: The magma causes 3d6 fire damage each round to any who touch it, and 1d4 fire damage each round to any creature starting their turn within 5 feet of it.
Encounter: Caged in the closed fingers of the fist is a small, human-like baby with deep violet skin and stubby black horns. It is immune to fire, and speaks in the voice of a wizened, worldly man – this is a demon banished to the mortal realm, trapped for eternity in the body of an infant. It asks only to be freed, promising great reward - a single attack dealing at least 15 hp damage to the fist breaks him free. It will deliver on its promise – the password to open the safe in “the brass room” is “Corux Voosh”.
6 - This dome-shaped room is carved with constellations whose stars are made of dime-sized crystals. DC10 to notice the crystals are worthless glass, and there are subtle air currents hissing from behind each one.
Trap: Attempting to pry out any of the crystals causes the air jets behind them to shoot them all simultaneously outwards at high speeds, striking everyone in the room with enough force to cause 2d8 piercing damage.
Treasure: The crystals shatter into dust which can be collected and used as a dose of itching powder (DC 10 WIS save or lose turn to uncontrollable scratching, 3 round duration).
7 - In the center of this dome-shaped room is a solid 8' tall, 4' wide rectangular block of pure white marble, with not a single imperfection to be found. Carved into the floor and ceiling is a single, extremely wordy, run-on sentence describing the entire life of a mortal-turned-angel named “Virgil of Corux”.
Treasure: Reading the entirety of the text from start to finish takes an hour; if it is read aloud, the marble block warps and crushes itself down into a fist-sized chunk shaped like an angelic figure (Virgil) – this figure still weighs as much as the original block (1 ton), but can be called upon to summon Virgil, who will do the summoner one favor before vanishing in a puff of smoke.