Tiaanamat

Tiaanamat was a large inhabited asteroid, orbiting the planet Akhaten in its rings. The asteroid had a molten magma ore.

Tiaanamat also played host to the famous Festival of Offerings, a millennial choral ceremony held when the planet's rings aligned that attracted pilgrims from the Sun Singers of Akhet from far and wide.

The Eleventh Doctor and Clara Oswald visited the vast, winding markets of Tiaanamat, as he had done previously in his first incarnation with his granddaughter. (TV: The Rings of Akhaten)