A fountain standing as a testament to a doomed alliance.

An underground network of massive stone arches and their skylit vaults support ruins of portico structures above.

An ancient knight and a symbol of the city's freedom.

One of the best-preserved medieval streets in Europe.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

Go inside to really appreciate this 500-year-old technological masterpiece.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

The ancient heart of Tunis is an enormous maze of narrow streets and alleyways.

Why a column on the entrance is inscribed with a verse from the Quran is one of Sicily's many mysteries.

The world's oldest known salt mine.

Terrifically morbid cemetary and site of famous Paracelsus' grave.

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

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

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

Five candy-colored villages on the Italian Riviera.

Perched above a grotto, this tribute to Mother Nature looks out into the ocean.

An old mining site that is slowly being reclaimed by nature.

Take a giant yellow bird cage to the top of Elba's highest mountain.

On rare days, this abandoned castle's gatekeepers open its doors, revealing the eye-popping splendor hidden inside.

A 14th-century abbey founded by a forest-loving order of monks now sits in the center of a pristine nature preserve.

Destroyed numerous times, this centuries-old bridge has always been rebuilt with its original design.

This medieval castle was home to a known tyrant and features several hidden passages.

Once an ancient Roman bath, now a hotbed of geothermal energy and a hub for energetic innovations.