A hidden stream deep in the mountains creates one of the largest tufa waterfalls in Serbia.

A Roman monument to their own civil engineering prowess.

A well preserved medieval fortress in Vojvodina.

Despite being pillaged and destroyed a number over times down the centuries, this historic church still sort of stands.

A maze of underground tunnels beneath one of the most beautiful forts in Serbia.

This mesmerizing medieval monastery-cave complex sits thousands of feet above ground overlooking a valley.

The bizarre rocks of Đavolja Varoš are the result of natural erosion.

Ride in 1960s style on the private luxury train Marshal Josip Tito used to travel around Yugoslavia.

This 14th century castle withstood years of battle but is now sliding off the hills into the Danube.

Structure built from the skulls of vanquished foes.

A tiny church on a man-made island in the Adriatic.

Carefully reconstructed after the Bosnian War, this 16th-century bridge stands as a symbol of the country's enduring multicultural heritage.

Two bulls enter. One leaves a champion—but neither loses its life.

A wellspring of natural Viagra found in Bosnia.

This picturesque monastery at the base of a cliff is a peaceful oasis open to all visitors.

This top-secret nuclear bunker hidden in a Bosnian mountain has been converted to a modern art exhibition space.

A peculiar museum that includes many drunken tales, a drunk driving simulator, and much more.

Art installations, derelict railcars, and endangered grasshoppers all call this south Berlin park home.

This monumental work of art symbolizes the coming together of a previously divided city.

Taste freshly foraged yarrow and black locust blossoms at this ambitious cocktail bar.

Concerts, art, offices, and a café in what used to be Berlin's first crematorium.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

One of the oldest cemeteries in Germany was originally used for victims of a cholera epidemic.

Berlin's beloved bear is immortalized at the Museum für Naturkunde.