Oasis (Marco Polo)
From Tardis Wiki, the free Doctor Who reference
In 1289, the First Doctor, Susan Ian, and Barbara arrived at a small oasis in the Gobi Desert, as they were travelling from Lop to Tun-Huang, with the ultimate destination being Peking. The oasis was a dangerous place for travellers to visit, owing to bandits that often camped nearby. (TV: Marco Polo)