date specified in canon
19th September 1835: The Sixth Doctor and Evelyn encounter Charles Darwin and the Silurians on the Galapagos Islands (in Bloodtide, a 2001 Big Finish audio – one of their best, IMHO).
From the Heart of Europe
Books, politics, languages and life
From what I gather Nollendorfplatz was the gay district when Kaestner wrote it!