Britain's worst subsidence hotspots are in London and the south east, according to analysis of subsidence claims by Direct Line home insurance.
Even Big Ben has a little bend. Documents recently published by parliament show that the top of its gilded spire is about one-and-a-half feet (nearly half a metre) out of line. The tower has been slightly off centre since it was built in the 19th century. Like many old buildings its position has been shifting imperceptibly for years as the ground beneath it subsides.