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

The first national memorial to honor all women suffragists stands on land where suffragists were once imprisoned.

A lightship turned museum, outfitted with artifacts from the vessel's past as part of the U.S. Lighthouse Service.

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

The former home of the man whose radical ideas changed the nation.

Get up close and personal at this Fresnel Lens.

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.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.

Volcanic stone sentinels stand watch at a Korean Bell Garden in Virginia.

A series of recreated fortifications mark George Orwell's path through the Spanish Civil War.

A once-secret library of Freemason history in Catalonia.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Read a book with a glass of wine at this classically restored bar.

The studio of Catalonia's most famous theatrical designer remains exactly as he left it.

Take an otherworldly journey in a school dedicated to out-of-body experiences.

Over 120,000 curious objects that have shaped our modern world.

Peruse rare tomes like poetry bound in pearls or books with branches and berries growing out of their spines.

This painted blacktop brings the classic arcade game to life.

The tale of a strong-willed woman who stood her ground when the commercial world came rumbling in.

Pick up all of the cosmic knick-knacks under the sun or take a creative writing course, all offered in this novelty storefront.

A huge musical sculpture and other art installations on the National Oceanic and Atmospheric Administration grounds.