The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

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

A small pack of an ancient, hairless breed of dog once believed to guide souls through the underworld lives on its grounds.

The Mexican painter Diego Rivera created this unusual museum to display his collection of pre-Hispanic artifacts.

This incredible college library is a visual masterpiece of mosaic art. It also looks kind of like a giant boombox.

This extraordinary art museum is like a secret world on the edge of Mexico City.

The famous artist couple lived and worked here, in two different houses connected by a bridge.

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

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

Museum preserving torture methods from the past.

This Bangkok high-rise looks like a rudimentary LEGO elephant.

Thailand's distressed elephants find peace at this Chiang Mai sanctuary.

This statue once earned the distinction as one of the "Three Major Disappointments of the World."

The largest pool at its elevation sits on top of one of the most expensive resorts in the world.

Singapore's landscaping project is home to 18 incredible Supertrees.

This collection of reclaimed landmines acts as both an exhibition of their deadly history and as a shelter for children affected by them.

Khmer Rouge's high security prison.

5,000 skulls in memorial to those killed by the Khmer Rouge.

These Depression-era WPA sculptures have made a couple of stops over the years.

Tiny treasures, giant murals, and strange sculptures decorate the windows and doors of this abandoned building.

A massive bur oak tree believed to be some 500 years old is the centerpiece of this quiet urban greenspace.