The Guardian of Tallinn.

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

The world's first and only escalator for lazy bicycles and their daunted riders.

The unbelievably opulent home built for an infamous newspaperman.

This stretch of beach along California's central coast is a busy highway for the largest seal in the northern hemisphere.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

It's not your typical library, memorial, or book store.

Centuries of crashing waves carved out this small hole in the rock, which lights up at certain parts of the year.

This cabin from the 1850s is one of the first structures built by Chinese immigrants in California.

The oldest lighthouse on America's west coast no longer needs keepers, yet they maintain the site anyhow.

Bizarre living fossil only grows in a small chunk of the Namib Desert.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

A statue honors the local legend that the devil helped build St. Mary's church after being tricked into thinking it was going to be a wine bar.

Micro-nation based around a nine-story high illegally built tower.

This Swedish sculpture park is a unique combination of ancient ruins and modern art.

Stockholm's narrowest alley is barely over two feet wide.

A man has revenged his true love's betrayal through tears and stone genitalia.

Sweden's first nuclear reactor, R1, can be visited 25 meters underground.

This poured-concrete water reservoir is a gem of modernist architecture well-hidden in a city forest.

Despite dreams of constructing this fairytale mansion, Albert Gotthard Nestor Cedergren never saw its completion.

The three colorful women depict characters from a beloved children's story.

Crystal chandeliers brighten up this dark underpass.

The palace for King Gustav III was never completed, but the foundation remains tucked away in this city park.

A rare surviving Victorian greenhouse designed specifically to house giant water lilies.