Haunted tuberculosis hospital built by the patients.

This abandoned naval battery stood at the ready as recently as the 1980s.

According to Hindu belief, this shallow island chain was created by a god with an army of monkeys.

Spend the night inside a two-story elephant villa.

The Egyptian-inspired last resting place of Lord Kilmorey.

The smallest pub in Britain was once a cabinet of curiosities and it still has the dead cat to prove it.

This amended headstone marks the grave of a participant in one of the most successful military deceptions of all time.

A floundering Polish shipyard was once the soul of the Solidarity movement that capsized communism.

Only known mainland rookery of the threatened Stellar sea lion.

Mine shafts and hard pastries await visitors at this massive mountain of salt.

One of the only memorials dedicated to journalists who died in combat.

This toxic spoil heap found a second life as a ski slope, popular film location, and wildlife haven.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

A German apartment building hosting as many trees as human occupants.

1898 German railroad depot museum with working engines, steam train excursions, and hands-on displays.

This tunnel entrance is built to resemble a grand castle but no one is quite sure why.

One of the largest public collection of historic armored and military vehicles in North America.

A 1940s nuclear reactor built to produce plutonium for the Manhattan Project.

This beautiful system of tunnels built into natural rock serves as a centuries old plumbing system.

These locks on North America’s oldest canal are named after a porcine rock formation.

Isambard Kingdom Brunel, one of the great Victorian engineers, was the driving force behind the short-lived atmospheric railway.

This Latvian shot factory is still used twice a year to manufacture bullets the old-fashioned way.

The world's tallest shot tower—maybe.

An engineering masterpiece, or “Scheme of Madness?”