It is against the law to obstruct the view from the top of this English burial mound.

This 135-year-old weather station studied the effects of the climate on human health.

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

This curious Tudor-era castle was once home to Napoleon's greatest adversary, the Duke of Wellington.

London's Victorian Tower of Babel.

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

This stream-carved gorge has inspired poets, hidden smugglers, and trained soldiers, all without losing its beauty.

The commemorative stone column conceals a secret laboratory.

Shiny Brutalist box commemorates a pioneer of electricity and houses a railway transformer.

A 26-foot shark sculpture—a statement about bombs—set off a municipal battle royale.

A monument to the thrice mayor of London who according to lore made his fortune by selling his rat-chasing cat.

The ritual has been performed uninterrupted for nearly 700 years.

This logic-defying 16th-century Tudor manor still stands to the delight and astonishment of onlookers.

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

An eccentric 18th century naval officer built a ship's quarterdeck on his roof, the inspiration for Mary Poppins's "Admiral Boom."

This unique bridge curls up like a caterpillar to let boats pass and then unfurls again to span a small canal.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

The oldest inn in England served brew to the crusaders.

A Roman spa buried deep beneath the City of London.

Once thought to be the mysterious work of a witchy prophetess, a well with unusual properties turns objects into "stone".

Hear the quietest sound from across the dome.

An unusual round church in London with a Templar past.

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

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