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.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

This foreboding building was the headquarters of the terrifying Spanish Inquisition in Mexico.

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

These museum grounds are a Dalai Lama-declared peace oasis.

Get a privileged view over Mexico City's Historic Center from a terrace right in its heart.

Once home to an aristocratic family and a workers' organization, this intricately tiled building now houses a chain restaurant.

Many people don't realize there’s a lot going on in—and below—the world’s tallest triumphal arch.

66,000 pieces of art, donated by one of the world's richest men.

This colossal ancient sculpture of the monstrous Aztec rain god has a literally stormy history.

The only castle in North America to ever house European sovereigns.

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

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

A herd of 150 bison live on California's Santa Catalina Island and are at the heart of an ongoing debate between environmental protection and economic expansion.

This mountaintop lake bubbles and steams in a perpetual boil, thanks to its direct link to the Earth's interior.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

This urban oasis is a marvelous meld of music and landscape architecture.

A neutrino detector built into the largest man-made underground cavity in the world.

Possibly the world's largest coin stands just outside of a Canadian science center.

A little slice of Florida face-in-a-hole kitsch, unexpectedly located in a small New Mexico town.

A beautiful geyser under environmental threat.

An architect's childhood fantasy treehouse made real.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.