Great Hall of Time
From Tardis Wiki, the free Doctor Who reference
The Great Hall of Time was the location of a portal to the Matrix. The portal was located above the debating table.
In the Old Times, Rassilon stood in the Hall and asked the Matrix who had the power to make Gallifrey fall, to which is usually responded that "only you, oh Rassilon" had that power. Once, however, the Matrix responded that Snowana also held the power, to which Rassilon responded by banished her to the Outlands. (PROSE: Snow White and the Seven Keys to Doomsday)
