Go London About.com:
Take a stroll along Leinster Gardens, London W2 and you may not immediately notice something very surprising. It may look like a normal row of terraced houses but there’s something very odd about numbers 23 and 24.
23/24 Leinster Gardens are actually dummy houses and there is literally only the front facade! A walk around the back reveals a gaping hole and a railway line.
Source & Connect: Go London About.com