Colorado's only true geyser is hidden within the San Juan National Forest.

A little-known hot spring haven right below the highway.

An architect in Aspen used psychedelics as his muse while building this mushroom masterpiece.

This enigmatic building features numerous architectural styles.

The site of the gruesome massacre—and maybe cannibalism—of five men, a tragedy that made Alferd Packer infamous.

A focal point of in Denver’s skyline for over a century, inspired by a Venetian basilica.

A unique arch graces the Dolores River Canyon near the Hanging Flume.

Metal water storage tank turned ethereal concert hall.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

Even in death, he's still your huckleberry.

A huge communist-era propaganda monument and mural that offers stunning views of the Mongolian capital.

This small town bank is very aware of its name thank you very much.

A late sculptor's last project was to turn this abandoned cement factory into a castle-themed amusement park.

This mosaic-covered bar is brimming with curated curios.

This "little gallery in the middle of nowhere" is housed in a 170-year-old horse barn in the Missouri Ozarks.

The first car-centric shopping plaza in the U.S. brought a little bit of Spain to downtown Kansas City.

University City's quirkiest resident lives in a park named after its first.

This wooded grove of beautiful hand-built stone grottos is a hidden gem within a shuttered Franciscan monastery.

This pristinely abandoned filling station on the edge of a graveyard is populated solely by unsettling mannequins.

This former small town was destroyed not by the motor oil it sprayed the ground with but by the toxic waste that was added.

This historic cliffside mansion uses a natural cave for air conditioning.

A creepy sculpture of a decapitated head invites viewers to see St. Louis through its empty eyes.

The world's largest man-made underground caverns offer unparalleled underwater wonders.

The history of the treatment of mental illness, illustrated in all its gory detail, and housed in an asylum.