Slough was a town located in England.

The Tenth Doctor decided to take Rose to Slough to visit a telescope, where they met Chevalier D'Eon. After travelling to Christopher Dalliard's house, Rose spent her time trying to find the aliens that the Doctor had located. She was then enchanted by Joxer and Hempel to be sold as a slave and managed to escape the ship and rescued Darcy and the rest of the slaves. (AUDIOThe Sword of the Chevalier)