Craco, Italy

A hilltop town founded in the 8th Century, Craco suffered earthquakes, wars, and the Black Plague for several centuries (give or take).. The final straw was a 1963 landslide that forced all residents to evacuate. There is still some interest in visiting the original city, even though it is deteriorating slowly. Craco hosts a few religious festivals each year between May and October, while off-season tourists can explore the city ruins and cliffside views

Crystal Palace Subway, London

In 1851, the Crystal Palace High Level Station was built to connect the Crystal Palace High Level Station with the famous Crystal Palace in Hyde Park for the World Fair. This subway station is currently hidden under a four-lane road in south London.. Sadly, the subway station was completely destroyed by a fire in 1936, but the Palace was not. The station has maintained its red-and-cream tiled roof and octagonal pillars that resemble Byzantine architecture. Several times a year, the Friends of Crystal Palace Subway conduct tours of the station – else, it remains one of London’s best-kept secrets