A striking public sculpture representing the period of martial law in Communist Poland.

The silly symbol for an underground protest group is now scattered around the city.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

In the midst of a living monument to Soviet social engineering, Polish Catholics built this church by hand.

The tallest tower in Cáceres's Old Town.

A cluster of granite granaries perched on stilts.

The beautiful, ornate weather station is the most popular geocache in Salzburg.

This castle has links to Portugal’s founding and struggles for independence.

A small but charming botanical garden that contains many exotic plant species.

A 12th century church completely covered in shells.

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

A unique military outpost carved into a rocky outcrop in the English Channel.

Fighting the British and making game shows for over 150 years.

Dead weights honor the dead of Portugal's fishing industry.

This small chapel is built of human bones and decorated with a golden skeleton.

This unassuming chapel in Portugal plays host to a ghoulish collection of bones.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

An 11th-century medieval castle cascades over the town of Numão.

This impressive rupestrian engraving dates back to the Upper Palaeolithic period.

Iron Age runes and ruins hide in plain sight along this Portuguese beach.

A peculiarly shaped brass sculpture hidden in a courtyard in central Lviv

Get past the gatekeeper's apartment and enter an elaborate hoax of a restaurant with a Masonic feel.

Ukraine's oldest operating pharmacy now offers guests a fascinating walk through apothecary history.