An underground paleo-Christian burial site composed of the remains of several cemeteries and Basilicas.

This beautiful 19th-century temple stands atop the ruins of its predecessor.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

300 years of pharmaceutical history on display.

Hungarian self-built castle.

A centuries old castle atop a dormant volcano houses museums devoted to both women and witches.

The world's largest historic armory was established by independent citizens to defend themselves from the wars of larger forces.

Double spiral staircases are not unheard of, but they are very rare.

Swarovski's museum/theme park is a fake diamond fantasia overlooked by a giant.

A 16th-century horror show built in a lovely Italian garden.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Water and windows define this defensive Italian well.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

A serious museum dedicated to two German comedians.

An early 20th-century bullring converted into a modern shopping center.

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

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

This impressive working clock made of 16,000 plants changes its flowers twice a year.

Coast along one of Japan’s mountain railways for coveted views of magnificent hydrangeas.

Legend holds eating just one of these black eggs can add seven years to one's life.

Dedicated to the armor and weapons used by the legendary Japanese warriors.

This enormous monument is one of the most iconic structures in Tokyo, rudely nicknamed "The Golden Turd."

Not quite the menace it once was, this monster still has some chops.

Once a black market electronics marketplace, now an otaku shopper's paradise.