A small memorial to a deadly night in Serbia that shook the world before it was swept under the rug.

Nikola Tesla's former home contains an homage hidden from plain sight.

A mysterious echo seems to defy the laws of acoustics.

An acoustic anomaly with a mysterious cause.

On the edge of this small Washington Park, a piece of the Earth's mantle has come to the surface.

A monument to the legacy of the man who created Spongebob Squarepants at the school where his passion for art and marine biology began.

Spies, love letters, and ghost stories have all left their mark on this home-cum-museum.

A former poultry store that looks like a giant duck and is one of the "seven wonders" of Long Island.

The ruins of a resort and casino sit on the banks of this blue hole spring that pumps 70,000 gallons of warm, clear water every minute.

The longest navigable underground river in the United States is home to countless blind and albino animals.

Fifty years after a “blast blasted blubber beyond all believable bounds,” this idyllic natural area commemorates the carnage.

For this chef, an active volcano is his oven.

The world’s highest ski resort was deserted after an 18,000-year-old glacier melted away.

Thousands of migrating monarchs overwinter clustered amongst the eucalyptus trees.

A massive volcanic plug is now a protected area that hosts a number of bird species.

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.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

The ballpark in "Pigtown" where the Brooklyn Dodgers made their name was replaced with a huge apartment complex.

This cavernous abandoned marble mine is popular with ice skaters in the winter.

A mysterious spot where the laws of gravity seem not to apply.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

Toy museum in a former tavern is the expression of one man's life pursuit of the aesthetic power of cartoon imagery.

A hidden beach at the end of a tunnel of mangrove trees.