Shur

Shur was the principal city of Ribos, in which the Crown Jewels were kept. Garron and Unstoffe met with the Graff Vynda-K in the castle of Shur, where they used a large piece of jethrik in their attempt to convince him to buy the planet from them. The Doctor and Romana visited the city in search of the first segment of the Key to Time. (DW: The Ribos Operation)
 * Some sources give the name of the city as Shurr.