Op-art architecture designed for happiness.

Baroque celebration of the end of the Great Plague of Vienna.

The beautiful baroque library of the Hapsburg empire.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

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

Daily jousts and dancing barrel makers in Munich's mechanical clock.

Originally envisioned by King Ludwig II to rival Versailles, Herrenchiemsee's "New Palace" remains half-gilded for lack of funds.

The prototype for all Nazi concentration camps.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A bizarre house filled with an astounding array of collections.

One street divides a single town that stands in two U.S. states.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

A monument to the military service of America's greatest traitor refuses to even name him.

A castle built for love, and abandoned due to heartbreak.

This Art Deco fortress in upstate New York gives Manhattan's vaunted examples of the style a run for their money.

More than 5,000 contemporary and "historic" mustards from around the world.

A mysteriously dark cemetery monument fuels stories and legends galore.

A bypass decorated with large wooden troll carvings.

This cave holds a surprisingly colorful variety of geological oddities.

A tribute to the twin ideals of religion and patriotism, built by a Catholic priest from rocks, glass, and innumerable found items.

A place of great reverence for Trekkies everywhere, a hero's future birthplace.

143 feet of leaping muskie whose mouth can be used as a wedding venue.

Paranormal activity on the great lakes.

The center of the only hemisphere that awards visitors with a commemorative coin.