Britain’s longest ancient monument, this great 8th century earthwork was built to mark the boundary between what would become England and Wales.

Centuries of human activity have forged an eerie landscape of ruins and craters on an exposed and windswept hilltop.

The only quarter of the Old City not dedicated to a major world religion.

The maze-like transportation hub contains abandoned areas, derelict stores, and a resident bat colony.

A tiny park in the middle of some big power politics.

Legend says if you stick your thumb in the hole and it gets wet your wish will be granted.

A fountain standing as a testament to a doomed alliance.

The ancient heart of Tunis is an enormous maze of narrow streets and alleyways.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

This cemetery features modernist statues as strange as its name.

This semi-secret storybook hedge maze is also the oldest garden in the city.

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

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

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

This viaduct serves as a reminder of World War II.

A sprawling Baroque park with 300-year-old hydro-pneumatic waterworks.

Lyon's miniature version of the Eiffel Tower was built as a statement in support of French secularism.

Lyon's "Wall of the Silk Weavers" is one of the largest murals in Europe.

A colorful piece of contemporary art cheerfully clashes with Lyon's historical architecture.

Hundreds of hidden passageways weave through the old quarters of Lyon.

Between Neo-Pagans and Neo-Nazis, these strange rock formations have a curious cult following and a very strange history.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

A winding path built in secret on the edge of the continent.