Underground hospital complex constructed by slave laborers during the German occupation of the Channel Islands.

A curious cave church carved into the face of a cliff.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

On this romantic tidal island reachable only at low tide the tomb of a famous French writer overlooks the sea.

In France, a medieval-style home pays homage to an intrepid explorer who discovered Québec.

Built for an exposition in 1915, these horticultural displays have stood the test of time.

An inconspicuous suburban street corner is the site of San Diego's worst air disaster.

This concrete sculpture features a woman opening her heart to showcase a beautiful fern.

A working steam clock, one of only a few in the world, located in Vancouver's Victorian Gastown.

A classic gold rush hotel can be expected to pick up some ghosts along the way, and the Golden North is no exception.

During the summer, surfers in Alaska take advantage of this inlet’s unusual water patterns.

A morbid gateway to an Alaska town prides itself on the hunting history it represents.

A hulking remnant of Alaska's industrial gold mining boom in the 1920s.

A trading post in the North Pole where children send letters.

One of the deepest blue holes in the world.

The site of a 19th century "dream city" that almost rivaled Chicago before being swallowed by the Indiana sand dunes.

A fantastical and futuristic temple of light built from nine monumental glass veils.

A beautiful deserted greenhouse in the middle of a park.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

High in the clouds of San Marino sits an ancient tower with some curious prisoner graffiti.

The only urban monument in the world designed by the great surrealist painter Salvador Dalí.

This semi-hidden Manhattan restaurant is based out of a loading dock.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.