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

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

These azure waters were thought to lead to the Mayan Underworld.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

This Hawaiian cattle ranch acts as a museum devoted to the island cowboys that predate the wild west.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

The spot where the namesake of the Douglas fir met his mysterious end on a Hawaiian volcano.

A controversial memorial at the place where Captain Cook met his violent end.

The yawning remains of a complex naval fortress still haunt this Australian shore.

After sunset the heart of Zanzibar's historic Stone Town neighborhood transforms into a culinary playground.

Stunning ruins of what was once the center of one of the greatest empires in East Africa.

If you were standing here on October 5th, 1950, you'd be dead.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

The world's oldest bookshop still in operation.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

On this island, you suck away your garbage via an elaborate pneumatic tube system.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

One of only two commuter aerial tramways in the United States.

A little lighthouse in New York City, surrounded by mysterious stories of insanity-driven construction.

Holding the most bodies of any cemetery in the United States.

Enormous one time fiber mill now houses local artists and small businesses.

One of New York's best collections of pinball is hidden in a secret bar in the back of this laundromat.