Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

This massive subterranean fissure is known as the "underground Grand Canyon."

Too much gossip or just missing curfew could land you in here for a couple of days.

After 11 years of reconstruction work, Slovakia's finest hilltop chapel complex is finally reopen to the public.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

Climb around the high waterfalls on series of iron ladders and bridges within the wildest gorge in the Slovak Paradise.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

The unusual sculptures are believed to be powerful political symbols.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

A misnamed well, with a deep dark past.

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

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

This memorial park stands on the site of one of the largest mass executions of the Second World War.

Nikola Tesla's ashes are held in a golden sphere, surrounded by his works.

Structure built from the skulls of vanquished foes.

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

An ever-growing literary collection housed in the apartment where the Russian author penned his final novel.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

This exclusive resort has completely covered a tiny Balkan island in a 5-star warren of guest rooms.

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

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

Breathtaking and huge 430 year old maps of Italy.