The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

Northern Ireland's Brobdingnagian stepping stones.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.

The land is home to swimming ponies and a legendary 18th-century treasure.

Massachusetts memorial to murder victim Elizabeth Short near the spot where she was born.

This abandoned NASA launch site is now a memorial to a trio of astronauts who were killed there.

Someone loved this song enough to carve all of its lyrics onto a tree trunk in a Berlin park.