There are plenty of terrifying things about London. Sky-high rents. Rush-hour Tube journeys. A thousand years' worth of undead souls, wandering the city's streets, graveyards, pubs and parks. London's history is staggering and, at times, grisly; it would be more surprising if it weren't a bit haunted. From the Enfield house that hosted one of the world's most famous poltergeists, to the square where the ghosts of 35,000 plague victims mill about each night, these spooky locales will send shivers up the spine of even the most hardened sceptics.