A luxuriant botanical garden below sea level.

Leaf through over 30,000 artists' sketchbooks in what may be the world's largest collection of doodles

This advertisement for talcum powder was painted on the rock face and has since defied removal.

Time travel with sweets across history at this research-based candy store.

Built in the 1850s, this church was of the first five churches constructed in Harper's Ferry.

This shale formation along the Appalachian Trail once inspired the third president of the United States.

The "All-Seeing Eye of God" symbol on this library is a clue to one of the many former lives of this building.

Summer in Scotland begins with a spectacularly wild and colorful event rooted in ancient pagan traditions.

This awkward aquarium sculpture is one of the strangest statues in Chicago.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

Built to defend Washington D.C. during the Civil War, this fort became a post-war nucleus for a thriving Black community.

This cannon dating to 1755 has stood guard at this suburban intersection since 1915.

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

America's first federal monument.

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.

Once the largest trading firm of enslaved people in the U.S., this building is now a museum that preserves Alexandria's dark past.

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

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

A superbly preserved example of Georgian residential architecture that was once home to one of the founders of Alexandria, Virginia.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

A massive, majestic mammal watches over pedestrians from his perch atop a former B.P.O.E. lodge.

Dine like an American revolutionary at Colonial Williamsburg.

This "common-as-dirt" museum celebrates the glory of normalcy.