Pyramid of the Four Pharaohs

A pyramid burying four ancient pharaohs worshipping four gods: Bastet (Bronze Obelisk), Thoth (Wood), Seth (Obsidian), and Anubis (Sandstone). Only appears on the ten days following the Feast of Bastet, at the intersection of the four obelisks, floating a few inches above the ground. Maybe the finder has to be wearing the four-part mask to gain entrance.

Based heavily on Entombed With the Pharaohs, an early Pathfinder adventure.

Ankara, the Anubis Pharaoah, keeps a crude heavy key of sandstone with obsidian horns in her sarcophagus, about 1 foot long. It magically opens the gates to the Morning City.