Tomb of Rassilon

From Tardis Wiki, the free Doctor Who reference

The Tomb of Rassilon, also known as the Tower of Rassilon or the Dark Tower, was a large tower in the Death Zone on Gallifrey.

The tower contained a crypt where supposedly resided the physical remains of Rassilon.It had three entrances: a front entrance, a door on the roof, and access from caves below.

There were a variety of obstacles and boobytraps which made the journey into the Tower complicated. (DW: The Five Doctors)