The ancient tomb acts as a calendar that keeps perfect time.

An ancient Egyptian temple in the middle of Madrid, Spain.

This trio of Australian rock spires may have inspired aboriginal legend or just modern tourism.

Three columns of volcanic rock shoot out of the ocean.

The only road through the heart of Glacier National Park.

An underground magnet for ever-changing street art.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

Tubing through a cave lit with glowworms is a magical underground experience.

A hand-built folk art installation covered with messages of God's love.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

A modernist landscape of water and sci-fi concrete.

The final resting place of a space program monolith.

Pop culture has helped to keep this iconic British building from being destroyed.

The highest bridge in America was built for an almost unnervingly small amount of money.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

Iceland's largest lagoon is home to stunning multi-colored icebergs.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

A crumbling hospital from the 1850s on Roosevelt Island.

This massive wooden building contains a giant Buddha, healing pillars, and tame deer wandering the grounds.

When ecosystems collide in the arid Southwest.

Dramatic river bend surrounds a natural red-rocked pedestal.

A toxic ghost town sitting atop a massive coal fire.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.