A first-of-its-kind circular bridge for cyclists.

These giant yellow bowling pins seem to be defying gravity.

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

These enormous, stern-faced statues greet visitors with lanterns, and sometimes costumes.

An alien church provides much needed silence in the midst of a Finland shopping center.

A subterranean house of worship carved right out of the bedrock.

A giant gorilla made of used car tires used to sit sentinel over a Helsinki college campus.

Northern Ireland's Brobdingnagian stepping stones.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

These murals stand as reminders to the troubled history of this Northern Ireland city.

Belfast's namesake river still winds below the city center, hidden from sight.

This massive monument has been telling the time for 150 years—at a slight angle.

A giant sculpture of the legendary "Salmon of Knowledge" celebrates the return of fish to Belfast's River Lagan.

The ship built to ferry passengers and goods to the doomed Titanic is now the last remaining White Star Line vessel.

These engineering masterpieces are a dominant feature of the Belfast skyline.

A museum marks and documents the site of the Titanic's launch.

One of the largest lenses of its kind ever created, this former ship beacon has been brought down to Earth.

It's good luck to be mocked by this monkey.

An collection of Chinese propaganda posters from 1949 to 1979.

A 20-meter (65-foot) robot towers over Tokyo Bay.

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

The Guardian of Tallinn.

Spend your honeymoon where the Devil had his wedding.

"There's nothing there," and other lies the KGB told us.