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

This unique museum cafeteria showcases the history and regional diversity of African American cuisine.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

When it comes to handsignals (and colonialism) rock always beats scissors.

The span is crooked and made from two older recycled bridges.

She stares out across six lanes of traffic, clutching a musket and infant with determination.

A 200-year-old bar with a cheeky name claims to have served Edgar Allan Poe his final drink.

A faded sign from the 1920s remembers Baltimore's resistance toward banning alcohol.

This working class sculpture pounds his hammer all the livelong day.

This grand old 80-foot sequoia towers above the buildings in the city’s retail center.

The tech giant built three enormous glass orbs in Seattle so employees could work inside a rainforest greenhouse.

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

Thirteen pastel palaces in downtown Charleston add a gorgeous splash of color to the city.

An outlandish shoe shaped house built by an eccentric millionaire.

What looks like a simple quaint estate in rural Pennsylvania was in the 18th century home to a small monastic community.

Don't get it twisted: This is the oldest pretzel bakery in the United States.

This jail which was in service for over a century is now open for curious visitors.

An Olympic hero stripped of his medals is buried in a town he never visited, which took his name after his death.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

This elaborate towering structure was once famed for its revolutionary height.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.