Giant, friendly pelicans in Central London, the most unlikely of places.

Catacombs turned marketplace.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

A historic London cemetery now serves as a nature park incorporating gravestones & memorial statues.

The quaint little store that is said to have inspired a famous Dickens novel was only given its name after the book was released.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

Ancient snack bar of the Roman Empire re-opened.

This bridge was constructed from the rubble of the infamous Bastille.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Scattered throughout London are ancient remnants of the city's former bounding wall.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

Eighty million natural history specimens call this gargantuan museum home.

Breathtaking and huge 430 year old maps of Italy.

A marvel of Byzantine engineering under the streets of Istanbul.

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

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Go inside to really appreciate this 500-year-old technological masterpiece.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The celebrated eyesore created by starry-eyed sweethearts.