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

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

This impressive chasm is one of the longest natural underground cavities in the world.

Historic medieval fortified city in southwest France.

French commune at the heart of conspiracies.

This religious complex carved into a cliff is steeped in legends of miraculous stags and the Holy Grail.

France's high-tech, future-themed amusement park.

This submersible road connecting a French island to the mainland is lined with safety towers for when the tide strands travelers.

12th-century holy complex shares land with a natural park full of heavenly waterfalls and raptors.