Italian cave with exceptional acoustics and an unsavory history.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Museum dedicated to the terror regimes of Hungary.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

The largest stone circle in the world has ended up bringing up more questions than it has answered.

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

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

See massive fossils that are over 200 million years old in northeastern Arizona.

A hand-built folk art installation covered with messages of God's love.

This giant temperature attraction created some giant electric bills.

A tree bears footwear on the loneliest road in America.

Quite simply the largest tree in the world (by volume).

This Scottish museum is the only one in the world to focus not on one religion but all of them.

A succession of eerily contemplative iron figures lead from a Scottish museum to the sea.

The highest peak in the United Kingdom has a history of physics, specters, and a pilgrimage of strange objects.

A church that bred legends, and served as an inspiration for the Da Vinci Code.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

Tiny effigies of the victims of Edinburgh's famous Anatomy Murders.

The final resting place of soldiers' loyal canine companions.

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

This stately estate house features a tower covered in a bright, modern mural.

Macbeth's infamous "Great Birnam Wood."