Imagine owning the only house on a billet of land and all that's around you is water, except maybe a single elevated roadway or narrow bridge.

Call it a private island, not like Castaway or Gilligan's Island but a place with 20-100 acres or so that's accessible by boat and maybe by car, too. Consider scenic views, a dock, boat ramp, woods, wildlife and a beach, too.

The odds of such a place on first thought would be unusual. But islands for sale with a single home are hardly unheard of, and while prices can be in eight figures, they also can be well below $1 million.

Realtor.com in a 2016 article listed eight private islands which were for sale right then.

"With the weather warming up and our thoughts turning to summer, we fantasized about the ultimate escape. A true getaway. Namely, a private island. Really. Think of the benefits! No more crowded beaches, sold-out hotels, or blackout dates," author Claudine Zap wrote.

They ranged from the astronomical, $95 million at Key Largo, Florida, to the bargain rate, $298,000 in Tower, Minnesota. "OK, OK ... owning an island in Minnesota might not have the same cachet as a Hawaiian oasis, but it has some solid selling points," she says. "An affordable price, for one, which gets you a main house, guesthouse, dock for fishing and swimming, and lovely views of the state park coastline."

Zap also notes that private islands can be pricey following the purchase. "After you score your island home, there can be extra expenses, including a caretaker’s salary, some upkeep, and usually a boat — and that gas isn't cheap. But the upside: 'You can own your own little piece of the world,' says Private Islands founder and CEO Chris Krolow."

Vladi Private Islands, a global company with offices in Germany, Canada, New Zealand, China, lists 35 properties for sale in the United States mostly in the Northeast. They include two Long Islands, in Michigan for $1,395,000 and $19.9 million in South Carolina; Whiskey Island in New York; and Potato Island in Connecticut. Along with islands, there are two isolated farms in Colorado and a 4,000-acre "oasis" in Arizona. And vacationers can rent 11 properties, including East Brother Island, California for $295 a day.

Meanwhile, Private Islands lists 135 properties in 24 states and Puerto Rico,on sites from 1 acre to 4,680 acres. Florida has the most private islands at 33 followed by Maine at 16 South Carolina, 14 and New York, 12.

"From Alaska to Florida, the United States is possibly the most geographically diverse country in the world," Private Islands says on its website. "The majority of American private islands properties are located near the eastern seaboard, especially in Maine, New York and Florida. Islands for sale in the US range from tropical Florida keys to rugged lodges in Alaska," it says.

"Naturally, the weather varies as widely as the country's terrain. Florida's proximity to the Caribbean means hurricanes are a seasonal issue just as winters in Maine are never conducive to water sports," according to Private Islands.

Among the deals is 1 acre Pine Island in Maine. Listing the sale price at $550,000, Vladi calls it a "private island on a 4,800 acre lake that abounds with endless recreational activities. Only 2 hours north of Boston and 30 minutes north of Portland, easily accessible. Savor the early morning sunrises and end the day with spectacular sunsets after a day of fishing for salmon, bass, trout or pickerel.

Pine Island is about three miles from the public landing or marina. There’s a cozy Hansel and Gretel style cottage with an upstairs sleeping loft, surrounded by cathedral pines that stretch to the sky with meandering paths around the island. Loons nesting on the beach are your only neighbors."