Uhlala

Uhlala was a planet in the Andromeda Galaxy that had a large art gallery. When the Tenth Doctor and Donna Noble visited the planet, it had very busy streets filled with traffic, appearing to be a metropolis.

History
The planet was shared by both robotic and organic life forms, including various robots, humanoids and a variety of unusual aliens.

Landmarks
Uhlala had a notable art gallery that the Doctor took Donna to visit. Among other pieces of art, the gallery contained a slab of grey marble in a glass container and a piece of machinery disguised as art that became a part of the device used to open the black hole, Sentilli. The latter was stolen by the Cult of Shining Darkness, along with Donna, using a transmat. The gallery also had a mirrored floor. (PROSE: Shining Darkness)

Behind the scenes
The name Uhlala was not necessarily the real name of the planet, as Donna stated that she didn't believe the Doctor had understood what the girl was saying when they asked for the planet's name.