Overlooking the Colorado Convention Center is this giant sculpture made from thousands of triangles.

This museum offers an actual time machine back through Colorado's past.

This Masonic lodge was the first major private building to be constructed in Washington, D.C. after the Civil War.

The "Key of Keys" for Washington, D.C. and the apocryphal landing place for the military campaign that started George Washington's career is now at the bottom of a well.

This bridge over D.C.'s Rock Creek Park is sometimes called the "Buffalo Bridge" because of its four buffalo sculptures, which were cast from a single piece of bronze.

View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.

Beneath unsuspecting visitors feet, a capsule containing pieces of America’s civil rights history.

The National Park Service’s best-kept secret with views that rival any in D.C.

This site commemorates the life of a Japanese scientist who dedicated his life to the discovery of diseases.

One of the last mosaic tile facades found in the city.

The hippo that stands on this university campus was once a drunken flea market purchase.

Single runway interrupted by a busy road that cuts across its middle.

In Asakusa, Tokyo's very own Walk of Fame.

Fascinating exhibits of prehistoric and ancient artifacts displayed with a uniquely modern touch.

Once home to one of the oldest banks in the world, this building is also where Marco Polo's famous travelogue was written.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

Stone markers on the campus of Gallaudet University commemorate a peculiar school tradition.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

Abandoned railway line circling the city of Paris.

The celebrated eyesore created by starry-eyed sweethearts.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

This Parisian gem is one of the most incredible ethnographic museums in the world.

The video game-themed street art first popped up in the French city.

The history of radiation is on safe display at the foot of a radiation science laboratory.