Located more than 600 feet beneath sea level, this tunnel boasts the world's first undersea roundabout.

Built in the early 70s, the ruins of dinosaurs are all that remains of a man’s dream to build a free dinosaur themed mini golf course

Built in France in the 1400s, this gothic chapel now resides at Marquette University in Milwaukee, Wisconsin.

Visit a prison tower used during witch tribunals.

A busy island at the center of the world that doesn’t actually exist.

The site of an early Arthurian battle and the dwelling-place of prehistoric people and (possibly) an ancient race of giants.

Structure built from the skulls of vanquished foes.

Grab a latte at the birthplace of modern American skateboarding.

This Hungarian stilt village is built in a lake that never freezes over due to the power plant that that uses it as a cooling pond.

A Route 66 filling station that was designed to resemble the Hagia Sophia, and is now the symbol of an arts district.

The Grand Canyon’s original airport, which once welcomed pilots like Amelia Earhart and Charles Lindbergh, lies abandoned.

The perfectly named cave drop is the deepest in the continental United States, almost matching the height of Seattle’s Space Needle.

Over 100 concrete munitions bunkers are all that remain of a Pennsylvanian village seized by the US government.

Accessible only by boat, this centuries-old island fort never saw troops or combat.

Designed to allow funerals to proceed over the River Dulnain.

Unruly residents were housed in this one-person cell until the Black Maria arrived.

Water of undetermined depth has attracted rare fish and cult leaders alike.

Also known as the Limete Tower, la Tour de l'Échangeur can be seen from almost everywhere in Kinshasa.

The equator passes through this tiny island in the eastern Atlantic.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

A stranded woman lived alone on this remote island for 18 years, inspiring the great children's novel "Island of the Blue Dolphins."

An underground world of gorgeous, palatial metro stations designed as a nuclear shelter complex.

The island where one woman reigned as a "queen" over 30-odd Japanese soldiers who refused to believe that WWII had ended.

A house mixing elements of Chinese and Mexican architecture stands as a tribute to the Chinese-Mexican bishop who lived here.