The remains of Alfred Nobel's first nitroglycerine factory can still be found on the shores of a Swedish bay.

The charming storybook building now houses a small police museum.

This declassified Cold War bunker hosts a large collection of Swedish aircraft.

This monument to one of the largest science fiction games of all time bears the names of hundreds of thousands of players.

This beautiful, historic church looks like something out of a simpler past.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

The summer tourists on these cliffs are thousands of seabirds.

A formerly glacier-tipped volcano that inspired none other than Jules Verne.

This mountain fissure hides a secret path to a secluded mossy grotto within the rock itself.

Three columns of volcanic rock shoot out of the ocean.

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

Iceland's "Smoky Valley" is a beautiful river that is shrouded in a constant cover of steam clouds.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

Sweden's southernmost prehistoric rock art is hidden just outside Gothenburg.

This castle ruin in the middle of nowhere is a gem for wildlife enthusiasts.

This fantastic cave remained unexplored until 1948 when three schoolboys discovered a hidden entrance.

"We Seceded Where Others Failed."

A monument celebrating the idea of reaching inaccessible places.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.