This structure, built more than 60 years ago to manage devastating seasonal floods, is known to attract a rare species of freshwater dolphin.

A dangerous narrow-gauge railroad once traced a route through this striking canyon.

A bronze statue of Mister Rogers in the neighborhood where he grew up.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

A small and somewhat hidden memorial to 68 local veterans of the Vietnam War.

Long buried under the 20th-century landscape, this lift lock of the Alexandria Canal is the lone remnant of an ambitious early American transportation project.

The well-preserved remnants of a bridge that once made up a WW1-era military railroad.

This homestead was occupied by Union soldiers, who believed the owners were signaling Confederate forces.

This church is known as "The Home Church of George Washington and George Mason."

This small pedestal marks the spot of the first lot of land sold in Alexandria, Virginia in 1749.

This twice-relocated "Usonian" home is among the smallest built by master architect Frank Lloyd Wright.

This brick-lined pedestrian walkway was once a railway tunnel used during the Civil War.

Taste the white whiskey that the United States' first president once distilled and enjoyed.

This church on a Tohono O'Odham reservation has stood since 1797.

The only museum outside of Australia dedicated to exhibiting the artwork of Indigenous Australian artists.

Anna Anderson spent most of her life claiming to be the lost Romanov child Anastasia.

The final home of the most famous horse of the American Civil War.

The maritime museum that boasts the largest nautical library in the western hemisphere.

This tree is a living witness to the beginning of the Civil Rights Movement.

One tiny triangular park commemorates the victims of a yellow fever epidemic—many of whom are buried right below the grass.

A cement mixer-turned-kaleidoscope in downtown Norfolk offers different views of the city.

This old-fashioned carhop restaurant gave the world the waffle cone.

The childhood home of the famous general's mother is now a small, walled garden.