A mass grave for victims of an airline disaster that led to much-needed safety improvements for commercial flights.

A stone pillar commemorates the surrender of the extraordinary Apache leader.

The famous polar explorer stands outside the Royal Geographical Society's headquarters.

This mysterious marker puzzles pedestrians and infuriates geographers.

The remnants of an early automobile route across shifting sand dunes can still be found in the deserts of Southern California.

Climbing this abandoned railway leads to breathtaking vistas of O‘ahu.

The world’s first statue of the late Apple co-founder.

Journey through the largest remaining peat bogs in the contiguous United States to see the wilderness as it once was.

This unique bridge curls up like a caterpillar to let boats pass and then unfurls again to span a small canal.

This strange portrayal of the state's first lieutenant-governor literally stands on its head.

Eat like a bird in a bamboo nest.

The highest pedestrian bridge in Singapore looks like a series of undulating waves rising between two public parks.

A spooky defunct railroad tunnel now part of a sprawling trail.

The underground mall's skylights look like they could be part of a spaceship.

A medieval castle in the middle of rural Texas.

A mysterious drive-in nestled in the forest that leaves little to the imagination.

This crumbling UFO is one of only a few remaining "moveable ski chalets" of its kind.

A registered historic landmark shrouded in unsettling local legends.

The man who wasn't there.

A modernist landscape of water and sci-fi concrete.

A 90-year-old underground water reservoir offers a more industrial kind of tranquility.

There is an unmarked red button hidden over Houston's Buffalo Bayou that is just begging to pushed...

Imagine having a street run right through your home, or better yet, a historic bridge three stories high.

This giant boulder is sandwiched between apartment complexes in upper Manhattan.