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

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

The 19th-century home of Count and Countess von Hallwyl is now a museum.

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

A temporary art piece to celebrate LGBTQ Pride is now a permanent part of Stockholm's traffic landscape.

Enormous ants wielding giant pine needles guard a Stockholm real estate company's office.

This granite monument at the site of an ill-conceived tourist attraction is built from the same stone as the Mormon Temple.

A golden plaque marks the site of the mysterious unsolved assassination of the former Swedish prime minister.

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

An ancient fortified mound raised over the millennia from settlements built one on top of the other.

The largest catacomb system in the world.

Featured in one of the most iconic scenes in cinema history.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

Quite possibly the oldest love poem known to humankind.

Inside the Wayne County airport is an amazing collection of lights and sounds.

Disused seaplane hangar gets a second life as the jaw-dropping home of Estonia's museum of maritime history.

The oldest continuously operating pharmacy in Europe.

This medieval Estonian tower provides access to a series of tunnels that have been home to soldiers, punks, and fine art.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

Hidden in plain sight, Sweden's official ordnance datum is now abandoned.

Sweden's "good old days" painstakingly re-created in a model village.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

This chimerical bridge/tunnel appears to dead end right into the sea.