Cavern of Axiom

The Cavern of Axiom is the lair of the androsphinx Kamaljiori, located in a secret location within the Frostweald.

Description
The cavern is hidden by illusions to most, but clues to its location are revealed via obelisks of Ioun within the surrounding area. The entrance to the cave is at the base of one of the mountains, carved into a triangular shape, and opens into a long, carved tunnel and a flight of stairs. At the base of the stairs is a circular room, with a ten-foot wide pool of water which glows with a blue light, and a stone tile floor. On one wall of the room is inscribed, in Celestial the phrase "Knowledge dost billow, all realms are the shore. The sky a window, the water a door."

The pool is in fact a tunnel of water and leads to a second circular chamber, made of deep blue marble. This chamber has four pillars around the entrance to the water tunnel, each with a carved lion head, facing outward. Also around the entrance to the pool, encircling it in gold, is a rim with more Celestial inscriptions; this one reads "Betwixt the chaos, our order reigns, the ones who made us, refined the planes. As ages die, their time an ember, the four endure, the four remember." The ceiling of this room is a mural, with a small hole in the center, surrounded by images of the elemental chaos.

Activating each of the pillars with one of the four elements causes the room to begin filling with sand. Traveling through the hole in the ceiling leads to a brick tunnel, that in turn ends in a pair of metal doors, inscribed with the symbol of Ioun. Through those doors is a third, square chamber that splits into three pathways. This room has a central pit, and appears to have some sort of shimmering web as well. The dividing structures between the paths are more obelisks of Ioun, and placing an Ioun Stone within one reveals a stairway that leads to a platform.

History
Vox Machina entered the Cavern of Axiom having learned from Osysa that her mate was there and could help them find the Vestiges of Divergence. They reached the final room, where they found the androsphinx. He opened various portals to the elemental planes, in which the party was able to find the letters of his name, and attacked them as part of a trial of worth. Vox Machina was able to solve the puzzle, and was granted Mythcarver as well as information about the locations of some of the other vestiges.

Trivia
While an important encounter occurs within this cavern, the name of Kamaljiori's lair was not revealed until the release of the Tal'Dorei Campaign Setting.