The creator of the carousel's bingo-pinball hybrid survives in California's oldest gaming establishment.

Built for an exposition in 1915, these horticultural displays have stood the test of time.

One of the largest trees of its kind in California.

This futuristic bridge is one of the longest self-anchored pedestrian bridges in the world.

North America's largest accredited model railroad museum.

This San Diego museum, housed in a former Navy training facility, is dedicated to preserving women’s historic achievements.

A sculpture of the famous photograph stands on San Diego's "Greatest Generation Walk."

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

San Diego's most historic and haunted home.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

An inconspicuous footbridge beloved by San Diego locals.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

This cheese shop also houses a museum devoted to Dutch dairy.

The history and future of cannabis.

This pub boasts a curious history and may have inspired a Dickens character.

The medieval woodcut-style artwork chronicles life in medieval London.

This Underground station has been a popular filming location for decades, even before it closed.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

Scattered throughout London are ancient remnants of the city's former bounding wall.

Hear the quietest sound from across the dome.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.