Human ancestor’s 3.6 million year-old footprints.

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

The palace for King Gustav III was never completed, but the foundation remains tucked away in this city park.

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

This small museum nestled inside a souvenir shop is dedicated to Sweden's most well-known toy.

This statue and park honor the Swedish chemist Jacob Berzelius, one of the founders of modern chemistry.

The composer known as the "Swedish Mozart" arranged to be buried in an unusual spot.

A rare surviving Victorian greenhouse designed specifically to house giant water lilies.

The final resting place of more than 200,000 people, this is one of the largest cemeteries in Europe.

These 18th-century paintings of Warsaw were used to reconstruct the city after World War II.

A statue honors the children who fought Nazis in Poland.

A menacing statue of this mythical creature can be seen at the legendary site of the monster's lair.

Warsaw's fantastically preserved gasworks...almost.

An artificial date palm stands as a memorial to Warsaw's Jewish community.

One of the world's largest collections of medieval religious art.

A scale model of the world's largest existing lensed telescope.

A 12th-century church with a medieval fresco and an intriguing “Greek runestone.”

Wooden cutouts of the fictional family from the popular Swedish comic strip take a stroll along the side of the road.

A hidden bathhouse in one of Stockholm's oldest and busiest neighborhoods is open to anyone who can find it.

A heated statue pays tribute to one of Sweden's great actresses.

This small statue hints at the incorrect origins of the lush landscape park surrounding it.

This stone obelisk is a relic of the 17th-century Swedish mile markers.

A competition inspired by Stephen King's psychological horror novel "The Long Walk."

A concrete Picasso in the middle of a student housing complex on the outskirts of Stockholm.