Central America's deepest lake is actually a volcanic caldera, surrounded by three volcanoes.

Hidden deep in the Guatemalan jungle is a turquoise paradise of natural pools, caves, and waterfalls.

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

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

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The romance of early commercial flight still fills this Art Deco destination.

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

A former major munitions plant that has been converted into a sprawling art space.

Outdoor exhibits explore the contributions of European, African, and indigenous peoples to American frontier culture.

At 207 feet, one of the world's longest continuous escalators.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

A terrace reminiscent of Rome's Spanish Steps is tucked away in a little park in Washington, D.C.

The only female equestrian statue in Washington, D.C. is a 15th-century French heroine.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

This rowhouse doubles as one of the most photographed spots in the nation's capital.

Outside the Department of Transportation, a collection of artifacts honors the history of how we get around.

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

Art deco landmark on the outskirts of Washington, D.C.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

Look closely and you’ll notice that the color changes a third of the way up the tower.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.