The watery grave of an impractical idea.

America's silhouette includes 100 square miles of wilderness jutting into Canada thanks to an old mapmaking error.

A riverside park built around the ruins of a massive dam that collapsed in 1909.

Minnesota's highest point is a scenic vista marked by a plaque and armies of mosquitoes.

This iconic water tower and failed bandstand is open for panoramic views once a year.

A stone face watches over the river.

A mapping error in the 19th century made loggers think this section of the forest was underwater.

This picturesque cliffside beacon no longer calls to sailors but shines once a year in honor of a famous shipwreck.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

A toweringly silly piece of modern art has been delighting locals since the 1980s.

A butcher shop in Minneapolis has all the meats and cheeses you’d expect from any of its kind—except that all the products are vegan.

This large midwestern cavern features impressive rock formations and an underground waterfall.

Half of a waterfall goes into the river while the other half seems to disappear.

This lab's maddening silence is good for business but bad for sanity.

The ravine where Jesse James supposedly performed an impossible jump to evade capture.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

This old train trestle and collapsed tunnel once allowed the railroad to negotiate the steep slopes of the Colorado Rockies.

These decaying bridges 1,000 feet high are a reminder of the skill it took to cross the Colorado Rockies by rail.

Unlike most arches, this geological oddity formed in a volcanic dike.

A prehistoric rock shelter that's literally in someone's backyard.

Each year, teams of the world's best snow sculptors have 65 hours to create frozen masterpieces.

In the middle of a suburban Denver neighborhood is a cave that once provided solace for a prominent Ute chief and his family.