A controversial blue hoop has been puzzling freeway drivers since 2013.

What was to be the world's most secure Cold War document vault ended up as just a few shallow caves.

The granite head appears to be deep in thought and half buried in the ground.

The ruins of the "20-year town" lay out among the mountains of Alberta.

Few other hotels can rival the grandeur of the Castle in the Rockies.

Canada’s surprisingly controversial monument to Dwight Eisenhower.

Fossils, railroads, and waterfalls!

An old world fairytale-land with over 350 fairy folk figurines hidden amongst 800 year old cedars.

Railways may have forged this quintet of lovely tunnels, but now they are open to hikers.

Opulent downtown movie theater now houses cars as an indoor parking garage.

The world’s largest Masonic temple was saved by the White Stripes.

To truly appreciate Detroit's landmark skyscraper, you have to step inside.

This empty Detroit high school was too expensive to maintain or destroy.

Berry Gordy Jr.'s old home was the original headquarters of Motown Record Corporation.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

The bones of an old zoo crumbling in the shadow of a new one.

Abandoned concert venue legendary for its rock counterculture.

The monster at the center of the Darwin Center Spirit Collection.

A little slice of Japan and its aesthetics in London's Holland Park.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

Collection dedicated to brands, packaging and advertising.

A network of concealed passageways lies within a busy London Underground station.

An small and easily overlooked archaeology museum chock full of Egyptian artifacts.

This hidden green space is the city's second largest conservatory.