The Winchester Mystery House
San Jose, Calif.

Background: Work on this home began in 1884 and lasted through 1922, when owner and designer Sarah Winchester, heiress of the Winchester rifle company, died. At one point, the property sprawled over 161 acres, but has since been reduced to just 4 acres.

Why it’s unique: Winchester was never a huge fan of blueprints. Instead, she preferred an on-the-fly design strategy, sketching rooms and architectural oddities whenever inspiration struck. Notable features include 40 bedrooms, three elevators, 47 fireplaces, 17 chimneys and 467 doorways. The house originally had seven levels, but an earthquake in 1906 collapsed three of them. Tourists now flock to the house to see its many quirks, including a staircase that leads straight to the ceiling.

222 House
Pembrokeshire, Wales

Background: This house, located within a national park on the southwestern coast of Wales, is sunk into the ground so the landscape remains nearly uninterrupted by its presence. It was completed in 1994 by design firm Future Systems.

Why it’s unique: With turf-covered roofing and siding, the 222 House fits seamlessly into the surrounding field. “This is exemplary sustainable design, where you are integrating the home into the site and minimizing the visual impact," architect Peter Koliopoulos says. The bathroom and kitchen are prefabricated pods that were lifted into the site during construction. An added benefit of the design concept is the geothermal insulation, which shields the home from wind and cuts energy consumption.

Free Spirit Sphere
Qualicum Beach, British Columbia

Background: This hanging room is the brainchild of Tom and Rosy Chudleigh, a Canadian couple who build these spherical living spaces for customers around the world.

Why it’s unique: The Chudleighs have two spheres hanging on their property: the Eve model, which has a diameter of 9 feet, and the Eryn model, which has a diameter of 10.5 feet. The spheres can be ordered fully loaded, equipped with plumbing, electricity and insulation. An average sphere weighs around 1,100 pounds, and it takes a crew of three about a day to install. The Chudleighs say that the structures gently rock in the wind, a nice thought -- depending on just how windy it is.

Chameleon House
Northport, Mich.

Background: Anderson Architecture completed this home in 2006 atop a hill overlooking a cherry orchard and Lake Michigan. The striking structure took less than eight weeks to build thanks to the use of prefabricated materials.

Why it’s unique: The steel frame of this house is wrapped in corrugated, translucent acrylic slats, allowing it to take on and reflect the changing colors of the landscape, like a chameleon blending into its habitat. Because it sits on a steep hill, the entrance of the home leads to the third floor, letting residents descend to the bedrooms or walk up to the living area.
Lake Palace
Udaipur, India

Background: This relic of architectural days past dates back to 1746, when Maharana Jagat Singh II commissioned it. Nowadays, it is a high-end hotel, outfitted with modern amenities and luxury suites.

Why it’s unique: The ornate palace sits on a 4-acre slab of land in the middle of Lake Pichola. Its exterior is made from white marble, which architect Peter Koliopoulos says isn’t exactly compatible with the natural surroundings. “You always want to develop design concepts that leverage, reinforce and highlight the natural features of the area. The scale and form of this building, though, are pretty obtuse,” he says. “Incorporating the marble just extends the oddity of the design approach."
Marathon Coach Custom Motorhome

Background: Marathon Coach is to motor homes what Bentley is to automobiles: pure luxury. A brand-new, fully loaded model can go for as much as $2.2 million, though used models can be picked up for less than $200,000. A custom order takes about 180 days to build.

Why it’s unique: For starters, each Marathon Coach has a minimum of five high-definition TVs, ranging from 7 to 50 inches in size. A 515-horsepower engine powers this house on wheels, and the stainless-steel chassis is covered under a 1.5 million-mile warranty. Other wild options include pullout barbecues, electric fireplaces, a second bathroom and a wine chiller. The major drawback is that the vehicle gets only about seven miles to eight mpg.
Amory Lovins’ House
Old Snowmass, Colo.

Background: Amory Lovins, co-founder of the Rocky Mountain Institute and a Popular Mechanics Breakthrough Award winner, is no stranger to eco-friendly initiatives, and this combined home and work space is a testament to his ingenuity.

Why it’s unique: The residential section of the building costs a measly $5 per month to power, thanks to the structure’s passive solar design, 16-inch-thick walls and krypton-filled windows. Lovins doesn’t rely on a boiler or furnace to heat the space; instead, two wood-burning stoves take care of the job. But most impressive, perhaps, is the greenhouse, which has churned out nearly 30 crops of bananas, as well as guavas, pineapples and other tropical fruit rarely associated with the Rocky Mountains.
The Crooked House of Windsor
Windsor, England
Background: Construction of this house dates back to 1592, but it didn’t acquire its trademark slant until 1718, when the structure was rebuilt using unseasoned green oak.

Why it’s unique: Sure it’s slanted, but what really makes the house stand out is that its basement had a secret passage to Windsor Castle, one of the official residences of the U.K.’s royal family. The passage was allegedly used for trysts between King Charles and a mistress, as well as for running supplies to the castle’s kitchen. The passageway has since been sealed off. Through the centuries, the crooked house has been home to various businesses, including a brewery and jewelry shop. It is now a restaurant.
Klein Bottle House
Mornington Peninsula, Australia

Background: This beach house, which was designed by the firm McBride Charles Ryan, was named the world’s best home at the 2009 World Architecture Festival awards.

Why it’s unique: A Klein Bottle is a complex mathematical concept that involves folding a cylinder into itself in order to create an unusual, spiraling form. This notion was the driving force behind the Klein Bottle House, which appears to bring the interior out to the exterior and vice versa. A steel frame was layered with cement and sheet metal, while the architects created a courtyard at the center of the house to allow wind to pass through easily.
Bubble Castle
Theoule, France

Background: Designer Antti Lovag long rebelled against traditional structures, and the Bubble Castle is a perfect example of his radical approach to rethinking the built environment. The bulbous compound sits on the southwestern coast of France.

Why it’s unique: There are no sharp angles or straight lines in this unusual design. Lovag unified the home with its natural surrounding by bringing outdoor elements inside, including palm trees and a waterfall. “This home is incorporating these outdoor rock croppings in a way that links them to the overall bubble concept,” architect Peter Koliopoulos says. The house has already been deemed a historic monument by France’s Ministry of Culture, despite the fact that it’s not even 50 years old.
The Mushroom House
Cincinnati

Background: This was the home and studio of Terry Brown, an architect who died in 2008. Brown, who was a professor at the University of Cincinnati’s College of Design, Architecture, Art and Planning, built the home between 1992 and 2006, bringing in students, on occasion, to contribute to the project.

Why it’s unique: Undulating woodwork, bizarre shapes and an array of materials come together to form a cohesive, albeit zany, structure. “This isn’t something you draw up and say, ‘Go build it,’” architect Peter Koliopoulos says. “When you’re doing something this custom, you’re fabricating and designing simultaneously in the field.” The fantastical design doesn’t stop at the front door. The interior is adorned with angular cabinets and multicolored rock walls. “This is highly personal and artistic … it’s just a different way of living and thinking,” he says.
Sliding House
Suffolk, England

Background: This traditional farmhouse was created by London-based dRRM Architects with one major mechanical surprise.

Why it’s unique: The 20-ton outer shell of this home can be retracted in six minutes, revealing a second, mostly glass, inner shell. Power comes from four 12-volt batteries that run a motor that pulls small wheels, built into the timber shell, along an old set of railroad tracks. This feature gives the owners control over how the house interacts with the surrounding environment, allowing them to make adjustments as seasonal temperatures and light cycles change.
Subterra Castle
Central Kansas

Background: Ed Pedin purchased this defunct missile silo in 1983, but it took about a decade of renovations to make it a livable home. Pumping out more than 8 feet of rainwater that accumulated while the site was inactive was one of many makeover challenges.

Why it’s unique: Not many homeowners can say their house once stored a four-megaton nuclear warhead. What was once the launch control station, Pedin says, is now a cozy living space. Transforming a nuclear launch pad into a residential castle has lots of benefits, such as an 11,000-square-foot garage and a 1,700-foot-long airstrip, which came in particularly useful when Pedin was experimenting with do-it-yourself ultralight aircraft. Since the completion of Subterra Castle, Pedin has become a mogul of sorts, creating 20th Century Castles LLC, a real-estate firm specializing in converting missile silos.
Steel House
Lubbock, Texas

Background: Artist and architect Robert Bruno has been at work on his steel home since 1974. Bruno has said that he wants the shape of the structure to be somewhere between animal and machine.

Why it’s unique: Most homes have an initial skeleton that is built upon throughout the construction process, but Bruno has approached this home like a sculpture, building it on the fly and making constant modifications. Architect Peter Koliopoulos points out that the four legs and cantilevered design minimize the structure’s impact by not disrupting the earth as much as a typical home design would have. Estimated weight of the structure is 110 tons.

Montesilo
Woodland, Utah

Background: Gigaplex Architects created this unusual and award-winning weekend home in 2006.
Why it’s unique: This house was created by joining two corrugated grain silos, the largest of which has a diameter of 27 feet. “This is an approach that is akin to sustainability,” architect Peter Koliopoulos says. “This silo home is a lot of fun and is a neat way to look at an existing product in a creative way.” With a modest size of 1,800 square feet, the designers saved space by placing the beds in cubbyholes that are cut into walls, each equipped with its own mini entertainment systems.

The Nautilus
Mexico City

Background: This seashell-shaped home was completed in 2006. The stone steps running along the shrubs lead to the front door, which blends into the mosaic façade.
Why it’s unique: Architect Javier Sensonian practices what he calls “bio-architecture,” a style that has led him to design buildings shaped like snakes, whales and several other creatures. The Nautilus was created to imitate the cephalopod’s shell, and its cavernous interior is filled with vegetation and small trees. “It’s not common that you would see a home of this design ascetic,” architect Peter Koliopoulos says. “However, it’s very enlightening and something that we can all learn from.”
Everingham Rotating House
Taree, Australia

Background: This octagonal house can rotate a full 360 degrees with the touch of a few buttons.

Why it’s unique: A rotating drive consisting of 32 outrigger wheels and powered by two 500-watt electric motors is used to spin the house on demand, a process that can take anywhere from 30 minutes to two hours. Geothermal heating keeps the house at a steady 71.6 degrees, and the electrical wiring and plumbing are centralized so that they don’t interfere with the house’s ability to move. The entire cost of the project was on par with the cost of a nonrotating house of comparable size.
Leaf House
Angra dos Reis, Brazil

Background: The roof of this architectural masterpiece looks like a giant flower with six petals, each of which covers a different section of the home. A curved swimming pool works its way through the house before culminating as a small pond stocked with fish and vegetation in the backyard.

Why it’s unique: Architect firm Mareines + Patalano designed the interior of this house to be free of hallways, providing ample space for the beach winds to blow through. “The idea of hallways stems from production homebuilding, which has so dominated our environment and marketplace that people see them as a standard," says Peter Koliopoulos, an architect with 26 years of experience and founder of Arizona-based Circle West Architects. “That is really unfortunate because great spaces are developed in a way that this home has been developed."