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

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

Rebuilt remains of a temple to Roman god Mithras.

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

The 2,000-year-old beam is tucked within the pedestrian entrance to the old London Bridge.

Only a few pieces remain of the structure that carried people and goods across the Thames for some 600 years.

An architectural oddity hides in plain sight on this iconic London bridge.

The first geometric self-supporting spiral stairs in Britain are a truly beautiful sight.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

The handiwork of a underdog clockmaker who solved an impossible problem for an Empire, and forever revolutionized seafaring.

This pub was 238 years old when it decided to revamp its image: It started serving Thai food.

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

Once designed as the entrance to Buckingham Palace, this structure was later relocated and stands as a victory arch.

A mysterious ancient elephant said to possess magic powers is now the symbol of a Sicilian city.

A sharp sculpture made of thousands of pieces of jagged glass.

An ancient octagonal weather station named for the eight Greek gods of wind.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

A man's head is enshrined beneath a statue near the first building constructed for the modern Olympic Games.

Where commuters walk through remnants of an ancient Greek necropolis.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

From cartoon characters to tiny tanks, a guerilla sculptor's little bronze statues are hidden throughout the city of Budapest.

This spire on an Austrian mountain is wrapped around a long spiral slide and has the world's tallest wooden observation deck.

Also known as the Blue Church, the building was consecrated to the daughter of Andrew II.