This colorfully-painted tunnel links two distinct parts of a historic neighborhood.

A giant yellow phallus sculpture hidden in the gardens of the Museum Boijmans Van Beuningen.

A huge teapot illuminates a home for the elderly.

An early 19th-century English style garden hidden in the Rotterdam cityscape.

Its town washed away centuries ago, this lonely tower by the sea tells the tale of a mermaid and a curse.

A dazzling temple featuring a towering 12-meter golden Buddha.

The first version of this stalwart construction appeared around 3,000 years ago.

The world's largest boar is a huge steel titan found at a French rest stop.

One of the world's largest collections of pharmaceutical artifacts.

An 11th-century fortress home to one of the most influential royal houses in medieval Europe.

This is not only one of the oldest collections in Europe, but also possibly the most beautiful.

Unusual, mushroom-like rock formations caused by weathering and water erosion, set to disappear, according to geologists.

The Tübingen University anatomical collection hosts an example of an extremely rare medical phenomenon.

Tiny memorials honor individual victims of the Holocaust.

The prototype for all Nazi concentration camps.

This dark, damp, perilous tunnel is the only passage from north to south Tajikistan.

This 18th-century sundial was designed to calculate the date of Easter each year.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

The curious underground history of keeping Paris clean.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

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

Famously misunderstood wonder of the ancient world