The massive cave church of Cairo's Zabbaleen community is one of the largest Christian churches in the Middle East.

The largest known Ancient Egyptian obelisk.

One of its engravings is believed to be among the first representations of medical and surgical instruments.

Gladiators battle and chariots race daily in the ruins of a once-great Roman city.

This unique collection collects pieces of art etched into thin pieces of stone.

A 30-foot stack of piano keys memorializes one of the greatest keys players in jazz history.

Prison made famous by The Shawshank Redemption has been out of commission since 1990.

The permanent home of Elektro, the celebrity automaton of the 1939 World's Fair.

Despite violent work crews and massive delays this abandoned canal tunnel was built to last into the modern day.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

Washington's iconic carousel has a nice piece of Civil Rights history.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

The oldest continuously operating fish market in the United States.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

The most decorated dog of World War I is preserved in the Smithsonian.

Perhaps the most scandalous statue of America's first president.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

A convincing little bit of ancient Egypt smack dab in Richmond, Virginia.

A small Richmond island dotted with the remnants of hundreds of years of history.

The iconic statue was moved to a new spot overlooking the James river after several years as a mascot for the local baseball team.

A former Confederate hospital serves as a remembrance of wounded and dead soldiers.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.