One of the newest mosques in a city filled with thousands.

This historic hotel preserves many treasures from its heyday hosting passengers on the Orient Express.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

Old Danish castle immortalized in Shakespeare's Hamlet.

A novel collection of medical curiosities housed in an 18th-century surgeon training academy.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

During the Soviet era, the spire of this longstanding church was used as a radio transmission tower.

"There's nothing there," and other lies the KGB told us.

Catholics make up 84% of Ireland's population but this Dublin museum remembers the small but important Jewish community.

The modern birthplace of Irish freedom.

The house where the writer spent his formative years.

A stunning Victorian abbey and walled garden on a lakefront.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This one has sailed five times as far as Sir Francis Drake's famous ship.

The majority of the museum's large collection is held in a storage space open to the public a few times a year.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

This coffee shop lies hidden beneath a historic church.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Eighty million natural history specimens call this gargantuan museum home.

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

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.