This fortress in Honduras was built to resist pirates, but its builders had more to fear from the British.

While the U.S. and Soviet Union were engaged in a space race, Poland built a UFO on the ground.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

An 11th-century fortress home to one of the most influential royal houses in medieval Europe.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

This elegant arc of a waterfall marks a religious turning point.

The most powerful waterfall in all of Europe.

Walk in the footsteps of the gods and straddle two tectonic plates.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Started as a kitchen garden, now the second largest botanical garden in the world.

This small roadside eatery exists in both the Northern and Southern hemispheres, as the equator runs right through it.

Where the White Nile River dramatically cascades between Lake Kyoga and Lake Albert in Uganda.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

This holy site either displays a centuries-old cross or a complete fake.

Once a ferry dock, radio transmitter, and now a new Greenpoint park.

Michael Jackson got Bad and Crocodile Dundee walked on heads in this iconic Brooklyn subway station.

A European-style bath house in Chicago.

New York City's only radical feminist independent bookstore.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

Two thousand artifacts from around the world collected by one woman who loved to travel.

An enormous, inside-out glass globe built in 1935.

Once called the "Polish Gold Coast" it is an icon of the neighborhood that bears its same name.