A ziggurat was a pyramid-like structure.
The ziggurat of Zababa was the largest temple in Kish. Uruk also had a ziggurat. Gilgamesh thought that Qataka's escape pod was a ziggurat. (PROSE: Timewyrm: Genesys)
A Dalek ziggurat was built on Kar-Charrat. Inside, Daleks placed themselves in cryogenic hibernation for centuries. An illegal salvage team was sent to investigate the supposed ziggurat, awakening the Daleks and causing them to kill everyone on the team except Bev Tarrant. (AUDIO: The Genocide Machine)
The Millennium Hall in London was a ziggurat. (PROSE: Millennial Rites)
The Unthinkable City had a ziggurat in its centre. (PROSE: Alien Bodies)
The Yemayan temple on Yemaya 4 was a ziggurat. (PROSE: SLEEPY)
Bev Tarrant investigated what appeared to be a ziggurat on Kar-Charrat, but was actually a Dalek hibernation unit. (AUDIO: The Genocide Machine)
PROTEC's headquarters was a massive glass ziggurat in Hades, the capital city of Pluto. (PROSE: Weapons Grade Snake Oil)
The Doctor's TARDIS had a ziggurat. (PROSE: Sky Pirates!)