Over 3km of caverns and caves at the Switzerland-France border contain the largest underground river in Central Europe.

A mythically themed self-built sculpture park.

A once-secret library of Freemason history in Catalonia.

A statue in the heart of Edinburgh honors a bear that served in the Polish military during World War II.

This massive memorial commemorates those who died in the Manchester Arena bombing.

This 19th century police station now puts the history of the Manchester City Police on display.

This multi-functional park is a marvel of civic engagement.

A building that survived WWII, possibly on the virtue of its name alone.

No passport is required to eat around the world at this elegant restaurant.

The house where the writer spent his formative years.

The world's oldest optical museum is an odd collection where the exhibits look at you.

The final resting place of a German diplomat's beloved companion.

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

This luxury shopping lane has been protected by its own tiny police force for over a century.

This hidden rooftop garden in downtown London offers a quiet respite from a bustling city.

This former train tunnel is filled with lines from a poem crafted by Robert Louis Stevenson.

The highest bridge in Myanmar was once the tallest railway bridge in the world.