This vast masterpiece of Moroccan architecture spreads across 20 acres.

Stalactites and stalagmites in a beautifully lit cave.

An underground city of salt.

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

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Fountain where visitors can earn a license to be mad.

The first botanical garden, a feather in the cap of the Grand Duke of Tuscany.

Fortified medieval tower house with lovely roof garden.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Medieval torture techniques with a modern conscience.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

Cozy basement bar sports an inventory of over 2,000 beers.

Brussels' favorite peeing boy has a sister.

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

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Steadily reminding Czechia of its past.

Macabre astrological automaton clock dating to the late 1400s.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Thousands of well-dressed mummies below a monastery.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

This one-of-a-kind archeological site is home to strange prehistoric ruins, the original use of which is still a mystery.