An abandoned saucer-shaped monument in the Bulgarian mountains.

Collection dedicated to funeral rites, equipment, and mourning rituals of the Viennese.

A patriotic medieval knight in driven-nail armor raised money for widows and orphans of WWI.

Op-art architecture designed for happiness.

This Austrian museum celebrates the work of famous forgers and their inimitable imitations.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

Climb inside an iron crystal magnified 165 billion times its normal size.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

A secluded fortress from the days of the Crusades that offers breathtaking views.

Deep in the Negev Desert, the world's tallest solar tower looks like a sight straight out of science fiction.

The only quarter of the Old City not dedicated to a major world religion.

This marvelous work of outsider architecture is built into the cliffs of an Israeli beach.

The tallest waterfall in the Judean Desert is named for its connection to a biblical figure.

This amazing ancient cave was kept secret for seven years to protect it from the public.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

Real bones which are said to have belonged to a Polish dragon.

Two stunning 17th-century libraries and a cabinet of curiosities.

A church of bones, decorated with 40,000 human skeletons.

Tel Aviv's popular neighborhood went though endless waves of transformation.

A stunning mosque owes its design to an Ottoman ruler nicknamed "the Butcher."

An autonomous community living in the southern Negev desert.

This historic rec center in the heart of Israel is a bastion of peace and togetherness.

One of the few guarded stops along the great spice route.