London’s first road overpass is so old that it was originally built for horse-drawn carriages.

One of London's lost rivers runs through a pipe over the tracks of this subway station.

A masterpiece of Art Deco architecture hidden in plain sight in West London.

The gigantic skull of a long-extinct species that once roamed the forests of England and Ireland.

One of the figures in this Celtic sculpture continues to puzzle archaeologists.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

Originally founded in 1654, this coffee house claims to be the oldest of its kind in Europe.

This historic pub is a hidden gem for fans of Lewis Carroll.

Just off the city’s central station hides a quaint lamp-lit alley into medieval Elsinore.

The shiny silver little brother to Copenhagen's Little Mermaid statue.

Old Danish castle immortalized in Shakespeare's Hamlet.

The world's first combination ski slope and power plant.

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

Early habitat dioramas and home of the elusive gaff, the skvader.

The Swedish flag over this small naval fort signals that the nation is at peace.

A king's bloodstained shirt is among the gruesome collection of artifacts displayed below Stockholm's Royal Palace.

Stockholm's deepest subway station is also a stunning ecological wonder.

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

The ruins of a monastery where Saint Bridget of Sweden had her revelations recorded.

A forest of immensely tall and unusually straight oak trees planted nearly 200 years ago to build naval ships that never came to be.

Enigmatic bug-like sculptures mystify drivers along a Swedish highway.

This quarry filled with 65 million-year-old limestone is now home to a nature reserve.

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

This pair of gilded girls atop an Art Deco building in Copenhagen were built to function as a weather indicator.