Huge stairway leads to this massive gallery.

The site of an early Arthurian battle and the dwelling-place of prehistoric people and (possibly) an ancient race of giants.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

A trailblazing sovereign nation tucked in the American state of Wisconsin.

Controversially restored in the 1970s, this giant 15th-century mosque is shrouded in legend.

This building has two facades of clashing architectural designs.

Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.

A striking symbol of the Bulgarian capital.

See how paper is made the old-fashioned way.

One of Bogdan Bogdanović's first spomeniks honors those who died during the People's Liberation Struggle in Macedonia.

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

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

These abundant, over-the-top monuments are so widely scattered that they define the entire compact capital cityscape, often leading to jokes about whether there are more statues than residents.

Sofia's legislative center is continuously reinventing itself.

"Holy Wisdom" overlooks the city that became its namesake.

A long, winding trek rewards you with a gorge so captivating it inspired a painting in the Tate.

A 30-acre garden inspired by the principles of modern physics.

This incredible viaduct was part of the Victorian railway boom and helped the Midland Railway navigate tough terrain.

An impressive Neolithic henge with banks nearly 10 feet high.

Though this large circular site is now named for the legendary king, its history dates back to the Neolithic era.

A little-known ruin with a convoluted history and a fascinating latrine drainage system.

Astonishing rock formations dot the Brimham Moor landscape.

This building was once a town hall, a fire station, a prison, a dairy market, and the target for two marksmen.

A perfectly running 230-year-old silver automaton and music box.