An old railroad grade built for the construction of Hoover Dam is now a recreational trail featuring several tunnels and sweeping views of Lake Mead.

These ancient sunken lanes were naturally tunneled into the soft ground by countless footsteps.

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

This restaurant's specialty is "a major enigma for food historians."

Used as an example in one of the first dictionary entries for "museum" in 1706.

One of Oxford's greatest treasures likely belonged to the legendary King Alfred the Great.

One of Europe's oldest libraries.

The fantastic charm of England's oldest botanical garden has made it a place of writerly inspiration for centuries.

These wire animal sculptures commemorate the exotic inhabitants that once called the Tower of London home.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

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

Preserved behind glass, the ruins of a medieval building used to store human remains.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

A haunting monument dedicated to the Royal Naval Air Service and the Fleet Air Arm.

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

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

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

A gruesome and mysterious ancient sculpture of a pagan deity from the Roman occupation of Celtic Britain.

This intriguing Bronze Age artifact spent centuries hidden within a Welsh faerie hill.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

This magnificently macabre shield shows the power of chivalrous love in medieval times.

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

This centuries-old pub boasts a collection of more than 4,500 snippets of neckties from around the world.