The Hveragerði fissure runs through this unassuming shopping center.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A series of three shiny letters mark the boundary of an old refuge for those being pursued by debt collectors.

A verdant 17th-century-style garden hidden along Edinburgh’s Royal Mile.

The colorful stairs are made with marble from the world's major quarries.

A labyrinthine network of chambers with a storied past hides below Edinburgh's South Bridge.

This was once a hall in which a 16th-century royal banquet was hosted by King James VI of Scotland.

This set of hot springs also comes with fantastic views.

This imprint of an old computer keyboard has a unique backstory.

The largest treasure hoard in Europe is contained in a castle that was bombed out during World War II.

Air-raid tunnels hidden beneath this opulent hotel provided shelter and an escape route—and one of the world's longest slides.

One of the oldest active carousels in the country—but it might be missed by all but the keenest-eyed boardwalk strollers.

Running since 1864, this clock has yet to be wound, one of the longest-running science experiments known.

Once part of a dam servicing an early 19th century grist mill, the tucked-way falls are a tricky-to-find urban oasis.

This twice-relocated "Usonian" home is among the smallest built by master architect Frank Lloyd Wright.

An unusual snaking bank of boulders caused by longshore drift.

This petite park lets visitors see and touch examples of fossilized dinosaur tracks.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

Walk in the footsteps of the famed astronaut at Purdue University.

For decades, the parade of apostles that left the Expiatory Temple of Guadalajara remained hidden inside one of the towers.

A room filled with frescos that make it seem like the walls are crumbling down while giants die in despair.

West Point’s only monument to a woman veteran stands above an empty grave.

These lights mark the area of Rotterdam that was bombed and burned in 1940.

This antique shop specializes in the history of print and design.