An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Artistic tombs, monuments, and a beautiful "Hall of Fame" lurk inside this cemetery.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

This grisly effigy displays an early Christian martyr who was skinned alive and beheaded.

A retirement home for soldiers that can trace its history to the Elizabethan era and beyond.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

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

At one of Berlin’s oldest churches, visitors can place mosaic tiles to help restore a medieval mural.

A striking 12th-century-style castle built on the edge of a cliff.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

One of the two original gateways into the Kasbah, this gateway is a nesting site for storks.

The first island in the world designated a light-pollution-free astronomical observation point.

One of the world's smallest prisons boasts just two small cells.

A statue erected in honor of the toadish nickname given to Jersey residents by the French.

An 800-year-old island castle in Guernsey's main harbor.

Underground hospital complex constructed by slave laborers during the German occupation of the Channel Islands.

An intricately decorated tiny place of worship.

This World War II bunker is now a shrine covered with sea shells.

This reconstructed ancient fort was home to one of the few horse training rings in the Roman Empire.

This historic Benedictine monastery brews a booze so toxic that it has often been blamed almost singularly for Scottish hooliganism.

This tangled English forest looks like something right out of a fairytale.

This ancient stone bridge dates back to the early Middle Ages.