This temple was created by the members of a remnant cult of Zathroth, for reasons not yet understood. The humans that hide in this place will do everything in their power to protect the secret that is guarded at the deepest level of the temple. For instructions on how to access it, check the Cults of Tibia Quest.
Note: Even though its entrance is located in an area accessible to free accounts, only premium players can enter the temple.
There's a parchment by the entrance with the following text:
At the end of the hideout, near the other portal, there's the following book: