Fortress Scindia was a fortress in the Madhya Province of India and the ancestral home of the Scindia family.
The Twelfth Doctor suspected that the whole fortress, or at least some rooms inside, existed four-dimensionally, in other words, existed simultaneously in several time periods at the same physical location and could be used to travel between these time periods.
In 1825, Rani Jhulka sneaked into the fortress and saved the Doctor from Vikas Scindia. (COMIC: The Swords of Kali)
