This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.

Maryland's first (and last standing) toll house on America's first federal road established the state as the "Gateway to the West."

The rooster who crossed the road lives on forever in Takoma Park, Maryland.

This one-room cabin where the young colonel slept during the French and Indian War.

The stone marker that Mason and Dixon placed at the eastern end of the famous north-south border they surveyed.

One of the oldest anatomical theaters in the U.S. still in use was once the site of an infamous cadaver riot.

Giant acorn-shaped 19th century gazebo from which suburban Washingtonians gazed upon the original "silver" spring.

A remarkable time capsule of American manufacturing deep in Maryland coal country.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

This scenic Maryland park was the site of one of the worst prison camps of the Civil War.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

After hundreds of years of settlement, this once-bustling fishing village sunk into the Chesapeake Bay.

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

A local farm's collection of unusual structures from a now defunct storybook amusement park.

A blank headstone topped with a pile of pennies marks the final resting place of the infamous assassin.

Walk a trail through a historic Quaker town that outlawed slavery in 1777 and was a major waypoint on the Underground Railroad.

The site where Poe "in great distress, and ... in need of immediate assistance" likely died.

The trials and tribulations of marking Poe's grave.

An astounding collection of medical specimens, including bits of President Lincoln.

This grave marks the passing of a historic Jane Doe whose identity remains a mystery to this day.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

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