An ancient Viking runestone hidden in plain view in Stockholm's old town.

Several cannonballs of mysterious origins decorate two buildings in Stortoget's main square.

Stockholm's narrowest alley is barely over two feet wide.

The site of the first battle of World War II.

A floundering Polish shipyard was once the soul of the Solidarity movement that capsized communism.

Inside this Krakow church, an explosion of psychedelic color.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

This grubby wall is said to be one of the Earth's esoteric energy centers.

Real bones which are said to have belonged to a Polish dragon.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

Also known as the Blue Church, the building was consecrated to the daughter of Andrew II.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

The bears of Bern have been a city highlight for over 500 years.

The world's largest second-hand graces a clock surrounded by constantly changing flower beds. 

Three bridges and one giant canyon make up this fantastic Spanish settlement.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

A lush indoor jungle fills this bustling Madrid transportation hub.

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

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

A fortified palace in the shape of a ship on the Thiou river.

Historic medieval fortified city in southwest France.