This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

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

A memorial for public executions that dates back to the 14th century.

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

The Great Fire of London and the regulation of one-way streets both started in this alley.

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

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

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

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

Once the fallout shelter of a dictator, this sprawling bunker is now a combined history museum and contemporary art gallery.

What happens when you cross a mayor and a painter?

Hundreds of thousands of concrete bunkers crowd Albania long after the fall of Communism.

This ominous Albanian fortress houses tanks and downed planes as a reminder of their victories over Western imperialism.

An Albanian monument to the Communism that nearly crushed the country is now a crumbling wreck.

A naturally beautiful, seemingly bottomless deep blue spring.

In the hometown of the Catholic saint and Nobel Peace Prize winner, a memorial dedicated to her legacy.

This fortress dates back to the 6th century and is also the site of a controversial abandoned restoration project.

A collection of miniature, symbolic sculptures hides in plain sight across Kyiv.

Dedicated to the lives lost during a fatal stampede in the Nyamiha Station.

These bamboo and rope bridges cross the Nam Khan River for six months every year.

This mysterious tower is said to enshrine a dormant seven-headed serpent that once protected Vientiane from destruction.

This French colonial post office is arguably the grandest in all of Southeast Asia.

Monument to a brutal, ineffectual US bombing campaign and a sobering reminder of the human cost of the Vietnam War.

This Melbourne bank has unique Gothic-style architectural features and is one of the most majestic operating bank branches in the world.