A vast Communist-era exhibition space in the Bulgarian capital.

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

A striking symbol of the Bulgarian capital.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

A subterranean house of worship carved right out of the bedrock.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Where the lovelorn find a home for their sentimental keepsakes.

A musical instrument played by the sea.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

This historic black and white monastery is one of Bulgaria's architectural jewels.

This whimsical statue dumps water on its head to symbolize knowledge flowing into his brain. Or maybe booze.

A giant bug impaled on a 75-foot-tall needle.

One of the largest aviation events in the world brings half a million aircraft enthusiasts to Wisconsin each year.

The Bong-area park police have asked visitors to please, stop stealing the signs.

Where experiments are conducted on all things wood.

One of the last surviving C-97s sits in a field in front of a Wisconsin inn.

The only Frank Lloyd Wright-designed structure in the architect's hometown.

The world’s largest collection of angel figurines includes 600 black angels donated by Oprah Winfrey.

A bronze plaque marks the site of the only show the "King of the Soul Singers" ever missed.

A museum celebrating the self-taught artist-environment builder.

A restaurant and lodge in northern Wisconsin which served as a clandestine hideout for John Dillinger and featured one of the most famous botched FBI raids in history.

Software company Epic Systems has created one of the strangest and largest workplaces of all time.

A bypass decorated with large wooden troll carvings.

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