Dr Barnes' $25 billion private collection of art and arboretum.

Alexander Hamilton’s creation caused quite a bit of controversy.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

The "Seinfeld" diner.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

This stunning iron gate designed by Modernist architect Antoni Gaudí is filled with mythic symbolism.

Belly up to the bar in Cowtown, don't forget to buy some boots.

A modernist landscape of water and sci-fi concrete.

One of downtown Berlin's last reminders of its Communist past.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The most visited, and possibly most controversial, museum in Germany.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

The blinking light atop the iconic landmark has been sending secret messages for decades.

On the Oregon coast there is a natural hole that seems to be draining the sea.

Legend says this sacred tree was a gift from goddess Athena.

The highway's southernmost spot is a beloved local attraction.

"We Seceded Where Others Failed."

An idyllic swimming pool tells the tale of Hemingway's trouble with women.

Visitors are welcome to enter this lush Key West sanctuary to entertain its plethora of rescued parrots.

A monument celebrating the idea of reaching inaccessible places.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.