A floating cat sanctuary on an Amsterdam canal.

The world's only museum devoted to the wonders of fluorescence.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

Countless stories attempt to explain Poland's mysterious J-shaped trees.

A haunting deserted hotel is a favorite with artists and photographers.

2300-year-old Roman road connecting the empire.

Pompeii's less famous neighbor is still revealing her secrets.

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

A submerged archeological park still holds the wonders of a Roman Sodom.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."