This Italian ski resort rose to fame when Benito Mussolini was held prisoner there and then rescued by the SS.

The highest point in Belgium is a staircase to nowhere.

An early 20th-century sanatorium, long abandoned and now being reclaimed by nature.

Located in the house where Gustave Flaubert was born, this odd museum has more to do with medical grotesquery than the Western novel.

Abandoned railway line circling the city of Paris.

Inside this small chapel tucked away in the forest is one of the most well-preserved Danse Macabre frescos.

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

For patriotic Russians, this memorial honoring the Soviet soldiers who died liberating Berlin in 1945 is the most sacred location outside of Russia.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

A towering monument in Spain has proven to be more labor-intensive than initially planned.

This fascinating and poignant museum chronicles every imaginable aspect of Spanish colonialism in the Americas.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

Earth's rocky history has rarely glittered so brightly as it does in this Spanish museum.

An ancient Egyptian temple in the middle of Madrid, Spain.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

An eerie collection of the surviving structures from a past celebration of the future.

Nicolas Schöffer's massive interactive sculpture was assembled in 1961 and brought back online in 2016.

Descend into the tunnels to experience the life of a coal miner.

A once-magnificent collegiate church is falling into ruin.

This giant urban staircase was built to keep the city's brave fighting men from getting waylaid in the red light district.

This abandoned Belgian fortress is purposefully being left to nature.

A marble Lucifer hides behind the pulpit of this Gothic cathedral.