An underground city of salt.

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

Remote and wild, Kinnarodden is the northernmost point of mainland Europe.

The gnarled remains of an exploded German bunker from World War II sit along a breathtaking fjord.

Watch a magnificent, ever-changing colorscape inside James Turrell's immersive work of art.

These 4,444 wooden steps straight up a mountain were built to serve a hydroelectric power station but these days, they're mostly used by hikers.

A stunning architectural yet functional feat, towering over Oslo.

The world's northernmost botanic garden has 25 collections of plants from arctic and alpine regions.

The Brutalist building harbors an unusual inverted dome that swoops down over its central sacred room.

The last fully functional fortress of Germany's World War II Atlantikwall.

Ruins of two abandoned stations destroyed by the power they sought to harness.

The grounds and buildings of an old wood pulp mill have been transformed into an innovative art park and museum.

This handsomely carved wooden church is more than 800 years old.

The largest cave in Northern Europe.

Norway's oldest cathedral still in use.

World's strongest whirlpool.

Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

The design of this beautifully crafted building was inspired by Norwegian glaciers.

At this Arctic outpost, get to know members of the indigenous Sámi community and meet their herds.

The world's northernmost aquarium looks like it has fallen over.

According to the locals, the sands of this secluded Norway beach are infused with gemstone particles.

A thin pane of glass keeps visitors from sliding off this futuristic skywalk.

Cold storage for agricultural biodiversity.

An artist's mausoleum with a haunting echo.