20. The Houses Of Parliament Were Built On An Island
Yes, that's right, the most famous landmark in all of London sits on an island. Specifically, Thorney Island. This "charming" spot was originally formed by a loop of the Thames and the Tyburn River, before the level of the land rose and the area was built over. Although Thorney Island has long since disappeared, the name lives on in Thorney Street, just off Horseferry Road at the back of the MI5 building. Back in the eighth century, documents described the island as a loco terribili (terrible place). The island's modern name is no less off putting, coming from the thorns that covered it.