Ancient volcanic activity made this into an exciting rockhounding site.

This massive redwood tree has a drive-thru tunnel carved out of its trunk.

This Las Vegas casino boasts one of only three spiral escalators in the United States—an engineering wonder.

A striking 12th-century-style castle built on the edge of a cliff.

The world's tallest church tower reveals a spectacular view to anyone up to the task of climbing the daunting staircase.

One of the world's oldest fossil exhibits is on display in a beautiful antique "naturalienkabinett."

Ruins of an aerial tramway that ran for only eight years.

World's largest barrel containing an inn.

Legendary site where an evil bishop was devoured by rodents.

It's good luck to be mocked by this monkey.

Lines on the pillar of Heidelberg's Karl-Theodor Bridge record the dramatic heights of past floods.

The jaw of one of humankind's earliest ancestors on display at an overlooked geology museum.

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

Every hour the doors open to reenact the legend of the heroic mayor who saved his town by drinking a gallon of wine.

Horrifically creative torture devices and shame punishments line the walls of this chilling museum.

A meteorite-bounded town in Bavaria.

A small marionette collection located within the dark cellars of an 11th-century Austrian castle.

The beautiful, ornate weather station is the most popular geocache in Salzburg.

The medieval network of canals hidden underneath the city is opened to explorers each year.

These 12th-century catacombs carved into a mountainside were a place of mysticism and Christian hermitages.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

Dress up like a miner and take a slide into the disco-lit depths of this once foundational salt mine.

This airport currywurst stand is made out of retro airplane parts.

Among the ostentatious rococo ornamentation of this church, an image of death cuts the life-thread.