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

The tombstone of an unfortunate explorer who disappeared in the Paris Catacombs.

A mud statue stands in the dark tunnels, seeming to hold up the weight of the city above.

Old ships and machinery fill a historic harbor in the city that's home to Europe's largest port.

From afar it looks like someone's hat blew into the water, but closer inspection reveals a giant floating sculpture.

A giant floating rubber duck-bunny painted with a different design every year.

A man has revenged his true love's betrayal through tears and stone genitalia.

Uppsala's adorable feline sign celebrates a popular children's book set in the Swedish city.

A rare rune stone dedicated to a woman.

It's always game time at Stockholm's only museum devoted solely to video games.

Legend has it this spring formed at the spot where a medieval Swedish king was killed.

This mysterious runestone embedded in a church wall is linked to the medieval cult of Saint Erik.

The official meeting point for the oddly named governing assembly of ancient Sweden.

The first thermometer made with the almost-universal temperature scale is backwards.

The second-largest collection of runic calendar staffs in Sweden.

Legend says this fabled well held part of a mythical Norse tree.

A large collection of ancient runestones decorates this university courtyard.

Ancient burial grounds of the wealthy.

The second oldest anatomical theater is housed in a museum of curiosities.

What looks like a birch tree smushed between two pieces of glass often confounds commuters.

This giant subway sculpture celebrates the fruit that inspired the theory of gravity.

A wooden street sign is the last remnant of this 400-year-old alleyway.

This centuries-old rooster survived a devastating fire.

If you visit Santa's village, you can get your passport stamped to show you crossed into the Arctic Circle.