When planning your next road adventure, consider spending travel nights in picturesque destinations along the highway. As explained below, instead the traditional hotel and motel rooms, try snoozing in a tree-top, under the sea, inside a big wooden dog, under a Native American wigwam or in a classic railroad car.

Key Largo FL: Jules Undersea Lodge, 51 Shoreland Dr., Key Largo FL 33037, www.jul.com You’ll need to be be in good physical shape for this challenge. On arriving, the hotel staff trains you to scuba 21 feet straight down to your immersed room. The unique underwater inn is located at the famed Florida coastal town where Bogie and Bacall starred in the 1948 movie drama with Lionel Barrymore and Edward G. Robinson.

Safely inside each comfortable underwater glass-enclosed room are the usual hotel furnishings, plus TV, refrigerator and microwave. On the sides and top are large porthole windows, with ever-changing views of exotic ocean-bottom plants and up-close schools of fish. Rates per night are from $400 a person.

Cave Junction OR: Out ‘N’ About Treesort, 300 Page Creek Rd., Cave Junction OR 97523, www.treehouses.com
This rustic bed and breakfast hideaway offers sleeping accommodations soaring 50 feet up into the treeline. Daytime activities on ground level include swimming and river rafting, as well as horseback and hiking trails. At night, in its outdoor theater, there’s music, magic and comedy entertainment.

Out ‘N’ About  offers many varieties of tree dwellings, from basic (no plumbing) cabins to luxury suites (full bath and kitchen), with prices starting at $150 a night, and all include full breakfasts below.

Cottonwood ID: Dog Bark Park Inn, 2421 Business Loop 95, Cottonwood ID 83522, www.dogbarkparkinn.com. If a two-story-high wooden inn shaped like a beagle appeals to you, this b&b in rural Idaho is worth a night’s visit.

During the day, there are various nearby activities, including horseback rides, hikes and jet boat tour of Idaho’s Hell’s Canyon. Rates are from $100 a night, and includes breakfast. Of course, family dog visitors are welcome.

Two Harbors MN: Northern Rail Traincar Inn, 1730 County Highway 3, Two Harbors MN 55616, www.northernrail.net
The train cars are all vintage boxcars, with the original weathered outside appearances. The air-conditioned interiors are brightly painted and furnished with attractive beds, sofas, tables and private bathrooms.

The inn is near Lake Superior, where facilities for boating and fishing are available. There’s also Gooseberry State Park for hiking and biking. Room rates are from $95, and include continental breakfast.

Holbrook AZ: Wigwam Village, 811 W. Hopi Dr., Holbrook AZ 86025, Old Route 66, www.sleepinawigwam.com
Since the 1930s, the strange sight of a field of concrete and steel replicas of Native American wigwams have greeted visitors to this Arizona site. Inside each 28-foot-high structure is a vintage wooden bed, chairs, TV, air conditioner and bathroom. Scattered around the wigwams are vintage cars, dating back from the 1930s to 1950s.

The entrance was once an old gas station, now with out-of-use old pumps still boasting 1950s prices of 15 cents a gallon. The Wigwam is now listed on the National Register of Historic Places. Rates start at $150 a night.