This World War I fortress is the perfect place to catch a Montenegrin sunset.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

A beautiful mountaintop mausoleum devoted to a Montenegrin icon can't seem to make everyone happy.

The now-overgrown beach resort was once frequented by Yugoslav military elite.

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

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

A former mental hospital founded in the 1930s by a eugenicist who advocated for the forced sterilization of patients.

A decommissioned submarine base makes a great space for graffiti art.

An abandoned textile factory on the "island of crows" was home to Estonia's first workers' strike.

A wooden statue of an Estonian pagan god and King of the Setos stands atop a sacred hill.

Hundreds of unusual wheel crosses poke above the earth in this small Estonian cemetery.

Legend says lovers who hold hands while venturing along this stone jetty and kiss at the end will remain together forever.

Abandoned Soviet base once stocked with short and medium range missiles pointed at western Europe.

Tombstones buried in overgrown grass mark the deceased occupants of this abandoned graveyard.

This old Estonian mine has been kept like a sprawling time capsule of the local shale industry.

Wars fought and wars won are remembered by these abandoned bunker ruins.

This Soviet-era "closed town" was a top secret uranium producer often left off of maps.

When a supermarket opened up shop within a medieval building it became protected by UNESCO on a technicality.

Centuries later, the victims of Great Britain's greatest hysteria are finally being remembered.

Fine dining in the bizarre world of Lewis Carroll.

A taste of the macabre Tokyo's ritzy shopping district.

These magnificently sculpted tombs represent Spain's own legendary version of "Romeo and Juliet."

Ask nicely, and stewards of a centuries-old charitable tradition will give you free bread and beer.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.