This vertical pinnacle in China was the inspiration for the floating mountains in the movie “Avatar.”

Tubing through a cave lit with glowworms is a magical underground experience.

The world's largest bioluminescent area was undiscovered by science until 2005.

Bioluminescence in the reefs of the Maldives causes the sea to glow like a starry night sky.

An abandoned railroad tunnel is now filled with bioluminescent bugs.

Australian Lake set aglow by Noctiluca Scintillans.

Ancient human remains unearthed around the iconic monument.

Legend says this ancient pagan site can cure all ailments.

Summer in Scotland begins with a spectacularly wild and colorful event rooted in ancient pagan traditions.

Home to the ancient Roman temple of a lesser-known Celtic god that inspired J. R. R. Tolkien and H. P. Lovecraft.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

The second-largest collection of runic calendar staffs in Sweden.

Stone carvings record the Norse myth of Sigurd, providing a glimpse into Scandinavia's transition from paganism to Christianity.

This 2,000-year-old stone maze is one of the oldest in the country, but its purpose is still a mystery.

A Viking man's tribute to his brother stands in Gävle's oldest church.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

This extraordinary Viking artifact has traveled throughout the city.

This tiny island featuring 9th-century Viking ruins is only accessible at low tide.

This replica of an 8th century burial ship actually sailed to Norway before returning home to Minnesota.

A replica viking ship from the Chicago World's Fair is still in dry dock in an Illinois park.

This tower pays homage to a legendary Viking fort established in Massachusetts that never really existed.

One believer transformed a local curiosity into proof of Vikings on the Great Plains.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.