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

A former major munitions plant that has been converted into a sprawling art space.

The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

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

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

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

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

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

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

The only place for a truly presidential dram.

The narrowest house in America is seven feet of pure spite.

An original apothecary from 1792.

This quirky curiosity shop takes its cues from the world's bazaars.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

A field of nothing but boulders which resembles a giant's gravel driveway.

This small-town Connecticut restaurant gives each diner a free book from its vast library.

One of downtown Berlin's last reminders of its Communist past.

These brass bunnies honor the rabbits that dominated the no-man's-land around the Berlin Wall.

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

Super-heavy Nazi architectural experiment.

A 12th-century fortress containing some of Berlin's oldest buildings.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.