The Needle

The Needle was an object one light-year long and 50,000 kilometers in diameter, with one end of it affixed to a black hole.

History
The Needle used to be Savar's TARDIS, but became caught in the black hole's gravitational pull and was stretched out when he tried to escape it.

Billions of years in the future, most of the people of the universe relocated to the Needle after a great disaster. (EDA: Father Time) One of the inhabitants of the Needle was Griffin. (EDA: Unnatural History)

A few decades before the universe ended, the Needle was almost completely abandoned. The Doctor traveled there in search of Ohm. (PDA: The Infinity Doctors)