The Map Room was a chapel in Tanis that revealed the location of the Well of the Souls, the resting place of the Ark of the Covenant, on a scale model of the city but only when sunlight passed directly through the headpiece to the Staff of Ra. The room was commissioned by Shishak so that the Egyptian god Amun-Ra could know where the Ark was located in Tanis, without having to look at it.
First uncovered by the Nazis and their diggers, René Belloq designed a replica of the headpiece based on the inscription of the original that had scarred its shape onto the palm of Arnold Toht in Nepal. Belloq wrote his calculations on the model and determined a location, unaware that the original piece had more directions written on the reverse. As such, he went digging in the wrong place.
Indiana Jones, in possession of the true headpiece, later visited the room with the Staff of Ra, in itself just a carefully measured shaft of wood, inserted it into the correct groove on the floor and waited for sunrise.
The sunlight hit the headpiece's crystal center, shining a beam of red light upon the model of the city, pointing to the Well of Souls. After measuring out where the location was in the model, Jones broke the staff and waited for Sallah to return to pull him out of the chamber.
Jones found a discarded map of Tanis left by Belloq, and kept it in his journal.
- Raiders of the Lost Ark novel (First appearance)
- Raiders of the Lost Ark
- LEGO Indiana Jones: The Original Adventures (Non-canonical appearance)