Ziggurat

"We stood with astonishment before a great rising staircase that was an echo of the wondrous ziggurat at Urnammu. That which scholars consider the remnants of the tower of Babel itself. At that moment we realised that the gods of Niamh were in truth men. The Babylonian fathers of the great empire of Byzantium."

- Expedition log

Ziggurat is one of the rooms in Aeternis.

Background
This ancient ziggurat was constructed millenia ago by the Byzantines, as part of their underground complex. It is a vital component of the Templar installation as well, connecting many of its crucial areas as well as being the only exit from the Grail sanctum.

Layout
The ziggurat is straightforward. The ramp leading down from it leads to the clock, while the opposite end, inside the ziggurat tower, leads to the cathedral. A ledge on the south-western end leads to Geffrye's studio. Interestingly, the ziggurat is very advanced. A shield-shaped relief on the upper part of the tower leads to the model room and can be used to freely navigate between the areas.

A one-way exit from Malik's lab opposite the entrance to Geffrye's studio is where you will exit after taking Geffrye's side at the decision point and surviving the lab. Last, after securing the grail, you will emerge inside the ziggurat itself.

The ziggurat will be flooded, either by you at the model room or by Tobias as you reach the decision point. The clock becomes unreachable as a result, and anything you left there.