Once the home of a hermetic monk, this cave now houses a small church.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

This memorial to a murdered empress took 20 years to design, then spent 30 years hidden away in storage.

This verdant, tree-lined Reykjavik graveyard is both enchanting and eerie.

Does this statue depict Thor, or Jesus Christ? Nobody knows.

This boat represents the promise of undiscovered territory, a dream of hope, and progress and freedom for Iceland.

Legend has it that this stone moves down to the river sometimes to have a drink.

Well-preserved, still-functional sliding wood doors from Ancient Rome can be found in this Vesuvius-stricken house.

The accidental discovery of this gilt bronze head led archaeologists to find the Roman Baths in the city of Bath

Ancient cave temple near a massive Buddha statue.

Besieged by war, this castle ruin has crumbled into a peaceful picnic spot.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

Watch cheese-flipping robots in action at this factory and museum.

This statue pays tribute to the iconic musician in the place where he recorded his final studio album.

A prison with a more than 200-year history.

Standing at the site of his former school, this sculpture celebrates Darwin's groundbreaking contributions to science and his deep connection to his birthplace.

These enormous concrete blocks played a vital role in one of history's most important days.

This restored 19th-century calender, a machine used in rubber manufacturing, commemorates the town's local industry.

One of the largest medieval barns in England and architecturally one of the finest.

Pivotal in the research of early British Bronze Age life, found near Stonehenge.

The oldest working mechanical clock in the world.

Small Easter eggs are hidden in the ventilation holes of the city's newest trains.

There are hidden patterns on the subway seats of some Stockholm metro cars.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.