Rings of Akhaten
From Tardis Wiki, the free Doctor Who reference
The rings of Akhaten was an asteroid belt around the sentient planet Akhaten. The asteroids were composed of solidified molten magma ore fragments. Tiaanamat was built on the largest piece of ore on the outer ring as a docking point. Amongst them was the inhabited asteroid Tiaanamat and the asteroid which the Pyramid of the Rings of Akhaten was located upon.