A museum in the former home of Marxist revolutionary Leon Trotsky.

Gilded heaven for philatelists and architecture freaks, still in full working order despite sitting atop tremulous ground.

Frida Kahlo's childhood home, now a museum of her life and works.

This spaceship-like Serbian monument reaches for the stars in celebration of the fallen fighters of fascism.

Outdoor escalators and art have helped change what was once a notoriously dangerous part of Medellín.

The religious shrine that Pablo Escobar's men would allegedly visit before completing a mission.

An unusual and beautiful form of mass transit serves the city's steepest neighborhoods.

This city park wants you to take your shoes off.

In the heart of Medellín, an artsy urban complex sets the stage for demonstrations and protests.

Three hundred illuminated pillars form an “artificial forest” in Medellín.

Home to 23 voluptuous and instantly lovable sculptures by one of Latin America's most celebrated artists.

Two identical statues by Fernando Botero, one blown to pieces in a terrorist bombing, the other donated as a gift for peace.

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

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

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

One of Mexico's youngest major cities still holds on to this structure representing its short modern history.

Located outside Medellín, this Colombian park focuses on conservation and sustainability.

A 10 million-ton rock once worshiped by the Tahamies Indians, accessed by an astounding staircase.

The Andean town where every single building is decorated with a brightly colored frieze.

Inside the cloister of the Temple of San Juan Bautista is a ceiling decorated with gold Baroque illustrations.

In Coyoacán, a pair of coyotes crown a public fountain in reference to the ancient Aztec name of the borough.

A Parisian exterminator's shop whose storefront displays stuffed rats hanging from traps.

Beggars were miraculously "cured" of their fake ailments when they returned home to this 17th century Paris slum each night.

If you look closely at the oldest bridge in Paris, you might notice hundreds of ugly faces leering from its sides.