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.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

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

This legendary dessert was served to Nobel laureates for decades.

Maybe the only restaurant in the world where your seat will be signed by a Nobel laureate.

It houses the remains of a 17th-century version of the Titanic.

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

Climb to the top of its spiral spire for spectacular views of Copenhagen.

This ordinary street was made infamous by a legendary visit from the devil.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

The art museum is decorated with creatively remodeled pre-Nazi swastikas.

This bridge's unique architecture honors nautical heritage and encourages self-awareness.

Pre-Nazi swastikas adorn the sculpted pachyderms flanking this brewhouse portal.

Bored potato-guarding Nazis etched their thoughts onto a brick storage building in Copenhagen's Meatpacking District.

Twisted trees shaped by coastal winds make this woodland look like something from a spooky story.

This antique thermometer honors the creator of the first universal temperature scale.

During the renovation of this bas-relief, the constructors added one unusual element.

A mysterious emblem tucked in an small alleyway is actually the coat of arms of a heroic medieval family.

The site of the first battle of World War II.

Several 12th-century ruins can be found inside this historical market.

This 700-year-old structure is one of the most unique architectural and historic monuments in Gdańsk.

One of the world's largest amber altarpieces is housed within this reconstructed medieval church.

Modern art commemorates one of the first military actions of World War II.