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

There are two dozen tanks just sitting in an open field in Lower Saxony.

This German bone house contains the remains of some 20,000 souls.

The prototype for all Nazi concentration camps.

This "floating railway" is one of the world's oldest monorail systems.

A fascinating insight into daily life in the Eastern Bloc.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

The most visited, and possibly most controversial, museum in Germany.

Unable to build support structures on glaciers, the engineers for this tramway were forced to design a unique system.

Folklore and history carved into Brittany's coast.

A colorful piece of contemporary art cheerfully clashes with Lyon's historical architecture.

An enchanting work of outsider art, full of whimsical sculptures and carvings.

An art world insider finds himself battling for his artistic home.

Walk inside a half mile long crevice right outside the town of Garmisch Partenkirchen.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

This public toilet built in the famous Amsterdam School architectural style is a Dutch national monument.

The tomb of a hard traveling saint is constantly covered in shoes as offerings to heal disabled youth.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Inside this Jewish cemetery is a memorial to soldiers who deserted the German army and were executed.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.