Beneath the southern end of the Golden Gate Bridge is the “Gibraltar of the West Coast,” a fort built to protect the San Francisco Bay from naval attack.

This ordinary-looking rock may have played an important role in a 16th-century Scottish battle.

The childhood home of Earth's alien chameleon is a humble Brixton flat.

This museum in San Francisco's Chinatown is one of the oldest and largest archives of Chinese American history and culture.

The arching stretch of London's longest street holds many reminders of the area's maritime past.

This medieval church tower has maintained its clockworks since the 16th century.

The first tunnel to be dug beneath a river, repurposed as an art and museum space.

The London pub overlooks where the Mayflower was moored before setting sail for the New World.

This unassuming building produced some of the world's most famous bells.

This hydraulic power system in London was, at one time, seen as a rival to electricity and the last of its kind to shut down.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

A faded reminder of what was once a common sight in London during the Blitz.

Remnants of a Victorian garden feature sitting in public woodland.

This stone spire holds a unique place in the region's history.

A Victorian natural history and ethnographic museum with wonderful turn-of-the-century, science-book-esque evolution displays.

A wonderfully eclectic Victorian aquarium lies in the basement of the Horniman Museum.

William Smith's iconic "map that changed the world" is hidden behind a curtain in the Geological Society building.

A four paneled, brightly multicolored mosaic adorns the side of this popular grocery store.

A hidden courtyard houses early 20th-century plaster masterpieces.

Paisley's oldest open green space contains a rather ostentatious fountain at its center.

One of the largest trees of its kind in California.

A giant fiberglass Muffler Man found new life as a rodeo guardian.

A tunnel that brings more than a century of history to life from the deepest parts of the Niagara Gorge.

Several bricks indicate the various flood levels this crossing has survived over the centuries.