Hundreds of signs pointing to the birthplaces of current Helsinki residents form stalactites on the ceiling of the cave-like Kamppi metro station.

An ancient stone structure that, according to legend, was built by witches.

Unchanged for decades, World War II-era bullet holes and nostalgic ghost signs still haunt this desolate train station.

One of the oldest continuously operating amusement parks in the U.S. is an open-air museum of Art Deco and neon lights.

A Google software engineer's Easter egg led to what may be the world's most unusual saved screenshot.

Contrasting the old concrete courthouse beneath, a modern and colorful residential marvel has emerged, stirring both acclaim and controversy.

Though this bridge was originally built in the 12th century, only one of its 10 arches dates back that far.

Ireland's most northerly island is hauntingly beautiful. Its lighthouse was the last glimpse of home for many Irish emigrants bound for the U.S.

This impressive chasm is one of the longest natural underground cavities in the world.

Switzerland's oldest public observatory is an important part of the Zurich cityscape.

A gorgeous, nostalgic café housed in a lofty old warehouse, lit only by petroleum lamps.

This wildlife refuge is home to more than 200 species of birds, as well as monkeys, lizards, and other wildlife.

The translucent turquoise hue of these natural swimming pools comes from a high concentration of minerals.

A heritage park that explores the history and ecology of Whangārei.

The site where the Emperor of Korea performed the long-forbidden "rite of heaven" to demonstrate his absolute sovereignty.

Legend has it the lovelorn tears of a princess and a shepherd boy formed the blue and green twin lakes in the Azores archipelago.

Inspired by a piece of concrete, these three pyramid-shaped buildings have been beloved Indianapolis landmarks for over 50 years.

An underground world of gorgeous, palatial metro stations designed as a nuclear shelter complex.

Provincetown's night owls flock to this 52-year-old pizza joint.

P-town goes wild for the malassadas at this 87-year-old institution.

This may be the world's only drive-through windmill.

An open-air museum exhibiting a total of 52 century-old buildings, recreating Hokkaido’s “pioneer village.”

A Soviet era flat that refused to conform to the dull gray standards.

This now museum began supplying water to Sunderland during the mid-19th century.