Azmael's palace

Azmael's palace was a huge citadel on Jaconda.

History
The citadel was built on a mountain and, by 2310, parts of it were more than two thousand years old. Centuries of piecemeal development meant that it was lacking in architectural and historical value, although a mosaic which took ten years to complete was declared an ancient wonder of Trilop Major.

The Doctor, in his fourth incarnation or earlier, once visited the palace and was given a tour by Azmael. This proved to be especially handy given that the interior contained mazes of dark corridors. (PROSE: The Twin Dilemma)

After the Jacondans surrendered to the Gastropods per Azmael's advice, Mestor the Magnificent took control of the palace and resided in its throne room. The Sixth Doctor arrived at the palace in his TARDIS with Peri Brown and Hugo Lang and helped defeat the Gastropods, killing Mestor in the throne room. (TV: The Twin Dilemma)