At just 25 inches at its narrowest point, it's one of the tightest streets in the world.

Two women with a flair for both adventure and artful clutter created this singular round home.

Latvia’s first skyscraper, nicknamed ‘Stalin’s birthday cake.’

A place of remembrance for the Prime Minister that met a violent end.

The last resting place of the famous Native American princess is marked by a haunting monument.

This foreboding medieval castle was twice besieged by barons rebelling against the English king.

Standing atop Wellington Hill is the world's tallest three-sided obelisk.

These remnants of Old London Bridge possess unique acoustics that allow for whispered conversations to carry from one side to the other.

This toxic spoil heap found a second life as a ski slope, popular film location, and wildlife haven.

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

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

What might be the oldest living tree in London has survived fires, bombings, and estate agents.

This building contains a door only used by members of the royal family.

Tucked inside a South Bank bar is an epic expressionist chronicle of the 20th century.

The ruins of a church destroyed by both the Great Fire of London and the Blitz, now turned into a peaceful garden.

An inverted staircase above the entrance to the Bethnal Green Underground Station functions as a memorial for people who lost their lives during the worst civilian disaster in the U.K. during World War II.

Sculpture of a legendary French dragon.

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

Some of the last remaining relics of one of World War II's most important invasions.

Now a memorial to merchant sailors and Titanic victims, this medieval church was destroyed by bombing raids in 1940.

This little-known wall in Southampton stands as one of the most unique and personal monuments to D-Day.

A half-mile-long stretch of medieval forts built after a devastating pirate attack persists amid the modern port city.

Dedicated to the five postal workers who died aboard the doomed ocean liner, this plaque was made from a spare propeller from the Titanic.

Some of the most enduring novels in English literature were written within the walls of this Georgian-era building.