The city walls of Salé lead to the ruins of this seaside "bastion of tears."

Morocco’s modern capital was once a haven for Barbary pirates, who went so far as to establish a republic of their own.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

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

A portal into the bricked up canal that runs through the heart of Washington D.C.

Before Nixon, "watergate" meant canals.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

The word "Watergate" will forever be associated with the infamous scandal in 1972, but this fountain is famous in its own right.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

An overlooked memorial honoring the local Washington residents who died in World War I.

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

The "lovely red Vega" of the legendary record-settling pilot.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

The institution is sitting on a goldmine of 21,000 paints, varnishes, pigments, and primers preserved for posterity.

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

This bare tree might not have leaves but it is constantly clothed in festive decorations left by mysterious local benefactors.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

Former self-sufficient mental institution now a planned community.

A subterranean world of tunnels links several buildings of this rare 19th-century asylum.

Prehistoric animals decorate this popular outdoor park.

The world's longest known cave system.

This park contains one of the largest concentrations of cedar glades, a unique and rare ecosystem.