This street might look a regular one, but check out the numbers 23 and 24. These facades are fake - the underground used to run behind them! Fans of BBC Sherlock might recognize the street from the last episode of Series 3 where exactly this feature of the street was mentioned.
Wikipedia https://en.wikipedia.org/wiki/Leinster_Gardens
Address Leinster Gardens, London W2 3WA, UK
Coordinates 51°30'44.809" N -0°11'0.007" E
