Oasis

An oasis was a pool of water in the middle of a desert.

Tegana visited an oasis to get water for Marco Polo's caravan, but instead he slit Marco's water pouch. (TV: Marco Polo)

A desert planet had at least one oasis on it, which the First Doctor, John and Gillian visited. (COMIC: Plague of the Black Scorpi)

The Andromedary was used on Bruvoldaveer to travel between oases. (COMIC: The Salt Solution)