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, one from the roof, one from the caves and the frontal entrance. There were a variety of obstacles and boobytraps which made the journey into the Tower complicated. (DW: The Five Doctors)