The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

This World War II bunker now survives as a documentation of the Nazi regime and war crimes.

A unique Holocaust memorial tells the personal stories of the Jewish residents exiled from greater Berlin.

A fascinating insight into daily life in the Eastern Bloc.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

A rare wayfinding portmanteau of “Street” and “Avenue.”

Concrete crosses scattered across the Arizona scrubland which were used to align spy satellites.

The highest point in Arizona is an oddly snow-topped peak within the otherwise arid state.

The wreckage of a deadly bomber plane crash can still be found near an Arizona peak.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

See massive fossils that are over 200 million years old in northeastern Arizona.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Rippling sand dunes frozen in the Arizona rock.

The wreckage of a World War II bomber is hidden high in the Colorado wilderness.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

Despite being one of the most photographed vistas in the Rockies these twin peaks are rightfully known as the "Deadly Bells."

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

When ecosystems collide in the arid Southwest.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

This naturally-sourced hot spring is now home to a clothing-optional resort.

The only tennis court that falls under the jurisdiction of the central bank.

100 years later, they're still down there.

There's an old indoor swimming pool hidden directly underneath the White House Press Briefing Room.

There just so happens to be a court even higher than the U.S Supreme Court: a basketball court in the building itself.