The largest self-built castle in the U.S., six decades in the making.

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

Strange red rock formations that have been attributed to a higher power for hundreds of years.

This super steep hike ascends 2,000 feet in less than a mile.

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

Once an unstoppable source of gold and silver, this town came to a grinding stop when the groundwater proved deadly.

A clear blue swimming hole with hidden caves, still unexplored.

Eastern zen meets Western grit in these four little trees growing out of a rock on Lake Tahoe’s Nevada shore.

The world's longest known cave system.

A popular rock that acted as a waymarker for American pioneers.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

This titanic Catholic church in Chicago is also a refuge of the fictional cult-favorite wizard detective Harry Dresden.

Once called the "Polish Gold Coast" it is an icon of the neighborhood that bears its same name.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

The ruins of a 19th century shelter run by the Independent Order of Odd Fellows.