Here are some of the world's most unique bed and breakfasts.
north of Galway City, Ireland
Constructed in 1648, this was the last fortified castle -- high walls and turrets -- built west of the river Shannon. Today, it's a bed and breakfast. The castle sits on 165 acres of woods and farmland but is only 15 minutes from Galway City's shopping and nightlife.
Dockside Boat and Bed
San Francisco, Oakland, and Long Beach, California
Choose your own private yacht from a fleet of boats which remain dockside and offer easy access to local attractions: San Francisco's Pier 39 includes more than 100 shops and 9 restaurants; Oakland's Jack London Square has 15 restaurants, a ferry to San Francisco, and a farmer's market on Sundays; and Rainbow Harbor in Long Beach is near the Shoreline Village shops and the Aquarium of the Pacific, as well as within walking distance of the convention center and restaurant row.
Kokopelli's Cave Bed and Breakfast
Farmington, New Mexico
This one-of-a-kind inn is built inside a man-made cave on a cliff. It's not easy to get to -- the entrance is reached by walking down a sloping path and intermittent steps cut into sandstone. There is a short ladder at the bottom of the path with three wooden steps that lead you to the flagstone porch.
Lizzie Borden Bed and Breakfast
Fall River, Massachusetts
Sleep in the actual home where Lizzie Borden is said to have axed her parents to death in 1892. At this unique Victorian inn, guests eat a breakfast patterned after the last one enjoyed by Borden's parents.
Moncks Corner, South Carolina
This monastery offers accommodations to people for short (one to six nights) retreats and long-term (30-day) stays. Visitors observe the same silence as the monks, eat the same vegetarian meals and can take part in the prayer services. The monks of Mepkin Abbey belong to the worldwide Order of Cistercians of the Strict Observance. They are commonly called Trappists, a reference to the mid-1600s monastery of LaTrappe in France.
Out 'N' About Treesort
Cave Junction, Oregon
Live in a treehouse -- and learn about the art of building treehouses. Rooms include the Swiss Family Complex, where the children's unit has an undersized door and built-in bunk bed. The adult unit is entered via a trap door. A combination deck/landing below the adult unit supports the swinging bridge to the kids' room.
Although it is not technically an island (a narrow strip connects it to the north end of New Zealand's South Island), this private, 6,000-acre sheep station offers a getaway as secluded as any other. Accessible by boat or plane, Pohuenui offers guests a variety of activities, including fishing, bush walking, kayaking, swimming, water skiing, sailing, mountain biking and hiking. Animals living nearby include dolphins, seals, penguins and several types of sea birds.