Men in rubber-soled boots serve as your "brakes" on this toboggan ride Hemingway described as "exhilarating."

At night, bats patrol this magnificent 18th-century space in search of book-eating pests.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This once-forgotten oasis in the middle of Lisbon was first created over a century ago quite by accident.

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

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

This charming candle shop has been in business since 1789.

This small chapel is built of human bones and decorated with a golden skeleton.

One of the world's largest model railroads is a mind-boggling achievement.

A former barn converted into a massive train diorama.

This delightful attraction features over a dozen miniature train layouts which you can operate and interact with.

A Jenga-style cylindrical tower of books that appears to go on forever.

Once the foundation for a mansion, these ruins now offer amazing panoramic coastal views.

This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

This architecturally eclectic fortress witnessed centuries of bloody turmoil, including the massacre of its ruling clan.

Ancient rock-hewn town that witnessed key events of Georgian history.

This extraordinary, multi-pillared monument depicts the fascinating history of Georgia.

A small but hugely whimsical theater where marionettes play out the "The Battle of Stalingrad."

A cluster of historic bathhouses built on the famed hot springs that gave the Georgian capital its name.

You'll find just about anything in this funky Tbilisi flea market.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

This ancient monastery complex was transformed from an island to a peninsula when the lake was partially drained.

Huge stairway leads to this massive gallery.