This pair of unsuspecting buildings are in fact the very first modern skyscrapers in Europe.

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

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

The scars of a remarkably organized public protest to save 13 elm trees are still visible in this Stockholm park.

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

One of the world's first dedicated bank buildings in the world is now the oldest one.

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

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

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.

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.

Stockholm's tiniest statue is of a small boy looking at the Moon.

A 130-year-old urinal is the oldest of Stockholm and perhaps all of Sweden.

Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

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

The house where a Danish physicist discovered the connection between electricity and magnetism.

Once a meeting point for great thinkers, and the midpoint of the country.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

Six beautiful wooden giants are hidden around Copenhagen.

An artist has turned what most people would consider a bathroom nightmare into a work of political art.

An old Danish political institution where members of government can grab a drink off the record.

Beneath Denmark's Højbro bridge, a bronze merman and his seven sons forever mourn for the mother and wife who left them for land.

Long before ultrasounds and modern testing, medical specimens like these conjoined twins helped physicians learn about congenital anomalies.

Visitors are treated to a stained glass kaleidoscope interior inside this work of art.