This sanctuary is home to donkeys who finally get to rest after a life of toil.

Take a sea tractor to the Art Deco hotel on the island that inspired Agatha Christie.

The Virginia farm where John Wilkes Booth met his grisly end is now largely forgotten.

When the rain falls, this drain system turns into a musical instrument.

The world's largest model of our planetary system.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

Built by prisoners of war, the largest small-scale model ever built includes eight miles of tiny streams that now sit abandoned.

Walk the whole Mississippi River!

No one's quite sure why there's a metal megaphone bolted on two rocks in the middle of the Mojave Desert.

Monty Python fans will recognize this abandoned mine as the Cave of the Killer Rabbit of Caerbannog.

A walkable map of the world, made from soil and stone by one man.

A New Zealand rubbish dump named after British comedian John Cleese.

Crouch down, stretch tall, and be sure to flail your legs to pay homage to the Monty Python classic.

A small granite monument marks where the borders of three countries meet.

The Arctic Circle runs through this isolated spot north of Iceland.

A giant concrete orb in far north Iceland marks the ever-shifting boundary.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

A high school astronomy enthusiast designed this model of our solar system to be traversed on foot.

Bronze plates placed around this Scottish fishing village form a true-scale model of the solar system.

You would never guess that before World War II this lonely field was a bustling German city.

The pits used to load the nuclear bombs onto the aircraft that dropped them over Hiroshima and Nagasaki at the end of World War II.

Concrete crosses scattered across the Arizona scrubland which were used to align spy satellites.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.