The highest bridge in America was built for an almost unnervingly small amount of money.

A tiny red pebble marks what may be the quietest outdoor spot in the United States.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

A French chateau, failed utopian community, odd museum, and Stonehenge replica in rural Washington State.

Sandstone rock formations that look like they belong on the cover of a progressive rock album.

148 feet long and in the middle of a verdant forest.

The beauty of urban decay, hiding some dark secrets.

One of the largest-ever mental hospitals now sits abandoned, surrounded by 25,000 unmarked graves.

The lush coastal city of Astoria is riddled with forgotten secret sidewalks.

An extraordinary mixture of natural beauty and man-made phenomena.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

An abandoned relic of the city's failed experiment with below ground transit.

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

An enormous park-like oasis, full of famous Chicagoans' graves.

European castle ruins in an American state park are actually the product of death and grief.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

Rare recess caves fill this unbelievably beautiful Ohio park.

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

A mysterious monument meant to be a guide into "an Age of Reason" was destroyed after an apparent bombing.

This massive wooden building contains a giant Buddha, healing pillars, and tame deer wandering the grounds.

An abandoned castle owned and ignored by Masons carries a cursed history.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

A religious-themed park filled with folk art to bring biblical stories to life that fell into disrepair and now being restored.