Forget the standard dirt patch in the woods. A new roundup of unusual US camping spots includes places where the sand hums, wild horses wander past your tent, and the night sky is so dark the nearest artificial light is 40 miles away.

In Hawaii, Polipoli Spring State Recreation Area sits 6,200 feet up Maui's slopes, where trails loop through eucalyptus, China fir and even coastal redwoods, with views across to Moloka'i and Lana'i on clear days. Tent permits run about $20 a night, and a rustic eight-bunk cabin goes for roughly $90 — just pack layers, because it gets cold up there.

On the mainland, the variety gets stranger. Idaho's Craters of the Moon National Monument protects three major lava fields on the Snake River Plain, with campsites from $15 a night in season — and free walk-in snow camping in winter. Nevada's Sand Mountain, a 600-foot dune beside Highway 50, hums audibly as the wind vibrates its perfectly sized sand grains; primitive camping costs $40 a week and it's free on Tuesdays and Wednesdays.

Assateague Island in Maryland puts you among roughly 300 wild horses, said locally to descend from shipwreck survivors — beautiful to watch from your campsite, but the National Park Service insists you keep at least 40 feet away. In Maine, the so-called Desert of Maine is actually eroded farmland exposing glacial silt, now fitted with a fiberglass camel, mini golf and cabins, domes and glamping tents from around $45 a night.

Stargazers should head straight for Cosmic Campground in New Mexico's Gila National Forest, a certified Dark Sky Sanctuary with about ten free primitive sites and four concrete telescope pads — no campfires or white flashlights allowed near them. Movie fans can visit the Rhode Island cove at Fort Wetherill where Wes Anderson filmed 'Moonrise Kingdom' (day-use only; camp instead at nearby Fort Getty). And history buffs can bed down at Wyoming's Hole-in-the-Wall, the plateau hideout once used by Butch Cassidy and the Sundance Kid, now part of Willow Creek Ranch.

There are odder stays still: Utah's Mystic Hot Springs offers soaking tubs, pioneer cabins and a Grateful Dead-themed converted bus from about $25 a night; a tiny bookable island cabin sits in the James River in downtown Richmond, Virginia; and New Hampshire's coast hides petrified 'sunken forests' drowned by glaciers 11,000 years ago, visible at low tide near campgrounds in Rye and Hampton.

Why it matters: if your camping trips have started to blur together, these spots swap the usual scenery for volcanic fields, outlaw hideouts and singing sand — often for less than a motel room. Most cost between $15 and $80 a night, and a few, like Cosmic Campground and Ape Canyon in Washington state, are completely free. Book early for summer, check seasonal closures, and don't feed the horses.