The winter home of millions of migrating monarch butterflies.

Underwater art project will double as a massive artificial coral reef to help regenerate the damaged ecosystem.

Superstitious? Discover the witchy side of Mexico through its largest esoteric market.

Extraordinary sculpture garden created by an eccentric English poet.

An Aztec snake god has taken the material form of an apartment complex.

This abandoned secret city is a crumbling wonderland of Soviet ruins.

Massive, unfinished broadcasting station stands as a monument to the fall of communism.

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

An unfinished complex built for children from around the world sits abandoned on the Black Sea coastline.

Eastern Bloc nostalgia, anybody?

A collection of art from Bulgaria's time as a communist state.

A flamboyant five-story building in Bulgaria resembles a crawling snail.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

An abandoned saucer-shaped monument in the Bulgarian mountains.

A futuristic, brutalist masterpiece that is also strangely prison-like.

Space-age monument to an early 20th-century uprising.

An abandoned resort in North Macedonia is a relic from the Communist Party of Yugoslavia.

A 11-foot former president stands on a Kosovo street that also bears his name.

A Serbian church lit by chandeliers made of weapons.

What happens when you cross a mayor and a painter?

Hundreds of thousands of concrete bunkers crowd Albania long after the fall of Communism.

An Albanian monument to the Communism that nearly crushed the country is now a crumbling wreck.

The complex has been abandoned since the Croatian War of Independence, barring a stint as a set for 'Game of Thrones.'

Gargoyle head that brings good luck.