In 1909, the steepest and most difficult piece of track on the Canadian Pacific Railway was replaced with a series of spiralling tunnels cut into the mountains.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

Site of the world's largest nuclear explosion.

Cold storage for agricultural biodiversity.

This abandoned mining village was predicted to resist decay longer than any other modern human settlement.

One of the largest collections of holy relics in the country.

A six-story-tall golden pyramid, surrounded by a moat.

The first spinning jail built in the United States is the only one that still turns.

This bridge was constructed from the remains of the first Ferris wheel.

This abandoned fishing settlement may well be the greenest village in the world.

This uninhabited volcanic island is the most remote in the world.

In the northernmost city in the world, it's illegal to be buried because it’s too cold for bodies to decompose.

This Arctic mining town is home to a cat that's spent years masquerading as a fox.