One of the most easily accessible examples of the rare 1960s UFO houses.

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

In the world's most bombed country relative to its size, this incredible organization helps pick up the pieces.

When the USA donated cement and funds to expand the airport in Laos, the Laotians built a massive monument instead.

Where America's first doomsday cult awaited the end of the world.

The humble field where the first Major League Baseball game was played.

A layered tribute to the work of mosaicist Isaiah Zagar.

At this former Prohibition speakeasy, electric birds signaled the arrival of hooch.

The childhood home of the Sultan of Swat is just a line drive away from Oriole Park at Camden Yards.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.

Conveniently located within binocular range of a nuclear bunker, the "summer camp" area was a painfully obvious spy house.

Its collection highlights the monumental tasks undertaken to map Queensland.

Started nearly 100 years ago, this science experiment just keeps on going, ever so slowly.

This abandoned railroad tunnel is now home to a micro-colony of bats and a ghost train.

A giant Australian fruit and tropical farm.

This small Australian town is considered home to the "Yowie" or the Aussie Big Foot.

The Australian terminal of the Pacific Cable that linked the continent to North America.

There's nothing shrimpy about the world's largest artificial prawn.

Once a farming community founded by the Italian survivors of an immigration scam, this colony is now a free camp and roadside attraction.

Australian holiday town hosts world's largest bowling ball.

Once an aquarium, this sanctuary now rescues sharks and rays from fishing nets.

This whimsical garden filled with fairies and incredible creatures has been enchanting children—and adults—since the 1970s.

These glyphs have long been attributed to ancient Egyptians, or maybe they're just a hoax.