Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

The tallest lighthouse in the Nordic countries was also the site of a bloody World War II battle.

Fortifications built for a Soviet invasion that never came now sit abandoned in a losing battle against nature.

Hidden deep in a forest is this geological wonder carved by glaciers.

This insurance company building reminds customers that witches, bears, and gnomes are out there, best be insured.

An abstract monument to a symphonic composer.

This set of concrete chambers resonates according to different notes of octaves.

A secluded art gallery hidden within the cellars beneath Tallinn’s medieval monastery.

A marvel of technology a century ago, this disused power station now offers a lovely glimpse into the industrial design of the past.

A towering monument to war, located on a beautifully peaceful hill.

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.

Started as a kitchen garden, now the second largest botanical garden in the world.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

This museum contains a vast array of puppets and marionettes from all over the world, featuring incredible works by Portuguese creators.

This once-forgotten oasis in the middle of Lisbon was first created over a century ago quite by accident.

A moss-covered statue of a Japanese Buddhist deity stands at a quiet temple in downtown Osaka.

A mysterious set of tunnels carved in the hills of rural northern Kyushu.

Founded over a thousand years ago, this shrine is said to be built on the site of a warlord's harem prison.

The largest volcanic caldera in Japan holds an entire city in its maw.

An unlikely hit, this museum is dedicated to the inventor of instant ramen and cup noodles.

The tallest bronze seated statue of the Buddha in Japan.

A remarkable lava formation encloses a line of Buddhist statues that can't be accurately counted, according to local mythology.

Japan's largest area of "pink moss" turns the hillside bright pink every spring.

A steaming, boiling hellscape sources Hokkaido's thermal baths.