If a stay in an ordinary B&B isn't enough, try one in a silo or on a submarine.
Once, four walls and a little Victorian frippery were all innkeepers needed to attract guests.
Then, they got creative.
Now, there's an inn room with eight walls, and a room with just one. There's a room with bars and a steel door. There are rooms on water and on wheels.
Who wants to stay in these singular digs? Just about everyone.
"They come, I'm telling you," says Roger Lee. He and his wife, Jann, added an 1893 caboose to the grounds of their 1903 Queen Anne, the Whistle Stop Inn in western Minnesota, and it was so popular they went looking for another one. Instead, they found a 1909 Pullman car and spent a year renovating it.
"We opened it up, and they stood in line to stay in the darn thing," he said. "So we said, gee, we should have another one. So we found another one 35 miles away from here and spent a year renovating that one. Now, we're tired."
The second Pullman, a burgundy-painted 1895 car called the Imperial, is the most popular, Lee says. Like the Palace Car, it has a double whirlpool, VCR and 750 square feet of space, but also a gas fireplace and its original stained glass and gleaming woodwork.
"There's a very strong addiction, I guess you could call it, to trains," Lee says. "Steam trains, that is - the old diesels are just not that romantic."
To many B&B aficionados, romance lies in the past, when valiant lighthouse keepers toiled in isolation, when grimy firemen shoveled coal into massive locomotives, when settlers struggled to build a town's first school or church.
Lighthouses score highest on the romance meter, and they've found new life as B&Bs all over the continent. On Lake Superior, the 1892 beacon in Two Harbors became the Lighthouse B&B in 1999 and is tremendously popular.
It doesn't have the luxuries of some inns, but as the last working lighthouse on Minnesota's North Shore, it has lots of cachet.
"When I go home, I tell the guests they're the keepers of the light, and they're in charge," says Judy Sellman of the Lake County Historical Society, which owns it and uses profits to pay for restoration. "A lot of them take it very, very seriously."
Other inns have pasts that are not quite so romantic. At the 1869 JailHouse Inn in Preston, Minn., which served as the Fillmore County jail for 102 years, one room is in a cellblock, complete with bars and metal door.
Even with carpeting, wingback chairs and its own video library, with such titles as "The Rock" and "Escape From Alcatraz," it's not a very inviting place, acknowledges proprietor Marc Sather.
Still, it's always been popular with guests, he says - families, groups of girlfriends and "people of various persuasions."
"It's more of a fun theme room," he says. "We've had former prisoners come back; they wanted to look, but they didn't stay." Other rooms are named after their previous functions: the Courtroom, the Detention Room, the Processing Room and the Drunk Tank.
"That's where the drunks were put overnight, and they could let themselves out the next day, just like Mayberry, U.S.A.," Sather says.
Today, guests needn't spend more than a night or two, to get a taste of the past or just for the novelty. Then, they can go home — or on to the next era.
Trains and cabooses
In western Minnesota, the Whistle Stop Inn B&B in New York Mills includes 1903 and 1909 Pullman cars with double whirlpools, gas fireplaces, VCRs and mahogany paneling, and an 1893 caboose with whirlpool tub and VCR. Two other rooms are in the adjoining 1903 grand Victorian. 800-328-6315.
Not far away, Maplelag cross-country ski resort near Detroit Lakes includes two cabooses. Rates include three meals a day during ski season; the cabooses also are available in spring and fall, but not summer. 800-654-7711.
Just to the north in Sparta, Caboose Cabins rents a 1968 Soo Line caboose that sleeps four and has a refrigerator, microwave, grill and fire pit. It's a block from the northern trailhead of the Elroy-Sparta State Trail and on the La Crosse River. 608-269-0444 .
Three miles north of Two Harbors on Minnesota's North Shore, the Northern Rail Traincar B&B, across the Stewart River from Betty's Pies, has 17 attractive rooms and a condo in 10 boxcars, connected by a hallway lined with vintage train photos and covered by a domed roof. 877-834-0955.
In the northwest Wisconsin town of Spooner, the Wisconsin Great Northern Railroad offers a Bed & Breakfast Train. Rates include drinks, hors d'oeuvres, a five-course dinner on a moving train and a hot breakfast.
For more about train inns and travel, see Riding the rails.
West of Marquette, Mich., Big Bay Lighthouse B&B is on the National Register of Historic Places and has seven attractive rooms. There's a sauna in the lighthouse, and spa services are available. 906-345-9957.
On Michigan's Keweenaw Peninsula, Jacobsville Lighthouse Inn B&B near Lake Linden has three rooms in the original keeper's house and two suites, one with whirlpool and one disabled-accessible, in a detached building. 906-523-4137.
Off the "Graveyard of the Great Lakes," west of Sault Ste. Marie, Mich., the restored 1923 Coast Guard Lifeboat Station crew's quarters at Whitefish Point Light Station has five modern and attractive rooms. 888-492-3747.
On Minnesota's North Shore, the 1892 Lighthouse B&B in Two Harbors is a working lighthouse operated by the Lake County Historical Society. It has three spare but tasteful rooms that share one bathroom, and there's a half-bath in the basement.
The Skiff House, on the grounds adjoining the visitors center, has its own bathroom and hot tub. 888-832-5606.
On the west side of the Keweenaw Peninsula, Sand Hills Lighthouse Inn near Ahmeek is in a 1917 yellow-brick lighthouse It has eight rooms, two with a whirlpool and one with a fireplace. 906-337-1744.
For more about these lighthouse inns, see Dwelling in the past.
In St. Paul, the Covington Inn was built in 1946 as a towboat and now is moored on Harriet Island, across from downtown. Four elegant rooms have fireplaces and superb views; the two-story Pilot House suite includes the pilot house as a sitting room and has a private deck. 651-292-1411.
Rates include a two-hour evening sail with picnic and a full breakfast. Twelve cabins have two bunks apiece and share two half-baths. 800-678-0383.
In southeast Minnesota, the JailHouse Inn B&B in Preston was built in 1869 as the Fillmore County Jail and includes a room in an original cell block. There are 11 other attractive rooms, four with fireplaces, three with whirlpools. 507-765-2181.
On the St. Croix River in Taylors Falls, Minn., the Old Jail B&B occupies an 1869 saloon and an 1884 jail on a hill at the edge of downtown and has three apartment-style suites, the Overlook, the Original Jailhouse and the Cave. 651-465-3112.
In the bluffs of northeast Iowa, the 1870 Clayton County Jail now is the Elkader JailHouse Inn , with three suites and a recreation room in the old cell block. 563-580-0041.
Rates include a guided tour that includes some areas that usually are off-limits.
The submarine sleeps up to 55 people. For more about the area, see Two trails from Two Rivers.
Just outside La Crosse in southwest Wisconsin, the brick Wilson Schoolhouse Inn was a country school between 1917 and 1965.
Now, its single classroom is an airy living room and gourmet kitchen, and the lower-level gymnasium holds two bedrooms, one with twin beds, and a sitting area with a pull-out sofa. 608-787-1982.
For more, see A cottage of one's own.
In northern Minnesota lakes country, in the tiny village of Dorset, the Heartland Trail B&B was built in 1920 as a schoolhouse and has six attractive rooms, named for different grades. 218-732-3252.
For more, see The dish on Dorset.
In the southwest corner of Wisconsin, just north of Galena, Ill., the Ambrosia Inn in Hazel Green includes a room in a 50-foot silo, taken from a nearby farm and fitted with a new top, paned windows and a red door plus a double whirlpool and gas fireplace.
The inn also includes a room in a gazebo and two century-old, chinked-timber log cabins.
For more about the area, an old lead-mining district, see Road trip: Southwest Wisconsin.
In central Minnesota, between Brainerd and Mille Lacs, the Nordic Inn Medieval Bed & Brew in Crosby occupies a 1909 former Methodist church built by mining magnate George Crosby. Its proprietor calls himself Steinarr, the Kraze E. Viking, and it has five Viking-themed rooms.
Steinarr specializes in groups, including women, whom he outfits in Viking wear and offers dinners with a variety of interactive theater. 218-546-8299.