This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

The house where John Wilkes Booth conspired with his co-conspirators.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

These unusual rooms on wheels are holdovers from the 1960s.

This pun was simply waiting to come to life, and one defense contractor made it so.

An eponymous directional signpost erected by the first president of the United States.

The ruins of this Thomas-Jefferson-designed mansion have been left to crumble since the Christmas Day they burnt down.

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

Lines from a walking song are etched into a rock in Natural Bridge State Park.

This campus chapel is Robert E. Lee's final resting place and a topic of debate about the legacy of the Civil War.

The eerie ruins of this feudal fortress witnessed the execution of 60 conspirators in 1387.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

A rococo room covered entirely in porcelain originally constructed for another royal residence.

What happens when you cross a mayor and a painter?

See no evil, hear no evil, speak no evil.

The only visible remains of this ancient Greek underground temple is its roof protruding from the earth.

During World War II, the Shroud of Turin was secreted to this remote southern Italian complex.

This beautifully restored fortification kept the city safe for centuries.

This medieval city gate is now a blend of the past and the modern world.

A massive bridge forms part of an aqueduct that was deemed an architectural wonder of its time.

The summer residence of a Spanish ambassador who brought viticulture to an impoverished region, sparking its transformation into one of the world's best wine regions.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

The remains of this medieval Roman road and lookout towers dot the rugged coastline of southern Lazio.

This celebration of Latvia’s freedom and independence avoided demolition over half a century of Soviet occupation.