This beautiful medieval Serbian monastery is home to frescoes, peculiar sculptures, and historical curiosities.

Stone age urban planning.

This natural monument has an origin story steeped in legend.

The oldest church in Serbia was also the ecclesiastical seat of the region during the Middle Ages.

A Roman monument to their own civil engineering prowess.

These natural stone bridges are the largest on the European continent.

Popular river that runs through the remote Serbian municipality of Leskovac.

This 15th-century Serbian Orthodox monastery also contained a school for illuminating manuscripts.

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

A beautiful 19th-century mansion slowly crumbled and became a 'ghost house' after World War II.

Through the colossal entrance to this cave you'll find limestone tubs and an underground waterfall.

A Red Cross memorial museum at the site of the Niš concentration camp that operated for four eventful years during World War II.

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

The ruins of this medieval castle on a foggy hill tell the story of a once-mighty empire.

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

A sinuous path among steep cliffs creates a stunning sight in southwestern Serbia.

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.

Turntable anonymously received orphans, alms, and groceries.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

This semi-secret storybook hedge maze is also the oldest garden in the city.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.