During World War II the Thorp building was guarded by the OSS, FBI, and US Navy because of the top-secret bombsight being produced there.

The last working windmill in the U.K. that has eight sails.

This old residential building was once the largest flour mill in the world.

These unusual rooms on wheels are holdovers from the 1960s.

This Canadian hunting lodge is a long way from home.

These ruins are all that remain of Tortosa’s lost coal gas manufacturing industry.

This amazing piece of modern art honors the hundreds of fishermen killed during Cambrils' "year of misfortunes."

The world's first purpose-built motor racetrack was destroyed by the outbreak of two world wars.

Long tunnels run under the ancient chariot racing circuit to the tower.

This magical space partly designed by Antoni Gaudi is one of the best examples of romantic gardening in the Mediterranean.

Soviet intelligence had a keen interest in the Cold War linguistic school at this old Scottish airfield.

One of the few surviving street funiculars in the world.

A great example of the inventive canal bridges that were deliberately split down the middle.

This tribute to a beloved cricket umpire is a magnet for risqué pranksters.

A memorial to the British politician who spearheaded the National Health Service.

This short white tower is all that's left of Scotland's first permanently manned lighthouse.

This old village lock-up is known as the "round house," but it is actually octagonal.