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.

The "Seinfeld" diner.

Now abandoned, the first public health hospital in the U.S. saw more than one million immigrants from around the world.

One of the largest underground systems runs under Canada's largest urban center.

The home, museum, and death site of Kodak's influential founder.

A near tragic event on this bridge helped inspire the classic film "It's a Wonderful Life."

Pre-Nazi swastikas adorn the sculpted pachyderms flanking this brewhouse portal.

The largest bottled beer collection in the world holds over 22,000 unique beer bottles.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

World's largest bell sits on the grounds of the Kremlin in Moscow.

A little sculpture with a large wardrobe.

Tintin's creator is celebrated in an immersive museum that's an astounding work of modern art.

Ride in 1960s style on the private luxury train Marshal Josip Tito used to travel around Yugoslavia.

One of the world's oldest olive trees, thought to be over 2,000 years old.

An Albanian monument to the Communism that nearly crushed the country is now a crumbling wreck.

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

A marvel of Byzantine engineering under the streets of Istanbul.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Bullet holes in the church wall are a reminder of the violence that followed the assassination of a high-ranking Nazi officer.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Go inside to really appreciate this 500-year-old technological masterpiece.