8 hidden gems across the US everybody should visit at least once

This giant mailbox, measuring 5,743.41 cubic feet, is fully functional and part of the Big Things in a Small Town workshop.

The World's Largest Mailbox, Casey, Illinois:

Modeled after Denmark and Spain, Solvang features Copenhagen-esque mermaid statues and Spanish cathedrals.

Mermaid Statues and European Influence, Solvang, California:

Home to the largest gypsum dune field in the world, covering 275 miles of white dunes.

White Sands National Park, Tularosa Basin, New Mexico:

Built in 1892 and made entirely of corn, this unique palace draws over 500,000 visitors annually and hosts a yearly festival.

The Corn Palace, Mitchell, South Dakota:

America's tallest underground waterfall, located within Lookout Mountain, is accessible by descending 260 feet via elevator.

Ruby Falls, Tennessee:

A castle built by Jim Bishop in 1959, featuring stained glass windows, wrought-iron bridges, and a fire-breathing dragon.

Bishop Castle, Rye, Colorado:

Created accidentally in 1964, this geyser spews water in vibrant colors due to various mineral deposits.

Fly Geyser, Northern Nevada:

A barrier island straddling Maryland and Virginia, known for its wild horse population and diverse wildlife including bottlenose dolphins and peregrine falcons.

Assateague Island: