Apart from suburban tract homes, America still has a healthy supply of homes that make you go "hmm." These are homes with stories to tell and questions to answer -- there's intrigue and mystery.

Two of these homes are built in honor of a loved one. Some of them are open to the public, some are private homes, and most of these in the list are even for sale Multiple homes on the list are energy efficient and even off the grid. Others are just off the wall, and some of those walls are constructed from some pretty unusual materials.

Location: East Hampton, New York

Price: $4 million

Bed: 3 Bath: 2 Sq ft: 3,700

Claim to Fame: The first U.S. example of reversible destiny architecture, or “architecture against death”

This house was designed with the goal that the occupants be disoriented, uncomfortable, and thrown off balance, because, the thought goes, when you get comfortable, death is not far behind. The thinkers behind this “life-affirming environment” are the artist-poet-architect/ husband-and-wife team Arakawa and Madeline Gins, who say they have decided not to die. This “life-affirming” is part of their plan to cheat the fate that awaits everyone else.

Built as an extension to a 1964 A-frame house based on principles of Frank Lloyd Wright’s architecture, Bioscleave House also comes with its own set of directions for use.

  

Location: Miami, Florida

Price: Not on the market

Claim to Fame: Billy Idol’s 1986 hit “Sweet Sixteen” was a tribute to the Coral Castle and its creator, and the video was shot at the Castle.

Ed Leedskalnin spent 28 years secretly working alone, mostly at night, with just hand tools to move 1100 tons of coral to construct this monument to the woman who jilted him the night before their wedding. It remains a mystery how he accomplished the feat. Since no one ever witnessed the construction, some have speculated that Leedskalnin had supernatural powers. Leedskalnin himself claimed to know the secrets used to build the ancient Pyramids.

Coral Castle was added to the National Register of Historic Places in 1984 and is now a museum listed under its original name of Rock Gate Park.

Location: Atlantic Beach, Florida

Price: $1.4 million

Bed: 2 Bath: 2; Sq. ft: 1500

Claim to Fame: It’s a disco-era house in a dune!

This design by architect William Morgan is ensconced within the earth, forming two double-height apartments carved into a sand dune. The apartments are entered at street level and a common stair leads to the upper floor’s entryway, bedroom and bath. On the main lower floor, the living, dining and kitchen with mostly built-in furniture open oceanside to a covered terrace at beach level.

The building was constructed in 1975 using swimming pool technology, a gunite-concrete shell anchored to a cast concrete floor. It’s also one of the original green roofs, as it’s topped by a mantle of earth stabilized by native landscaping which helps to maintain a 70-degree temperature inside.

 Hammargren Home of Nevada History

Location: Las Vegas, Nevada

Price: Not on the market

Claim to fame: Robin Leach called it “the most interesting home in the world.”

This residence is actually three houses that form a compound of curiosities. The first is a planetarium and celestial observatory in one-third scale model of a Mayan pyramid, the center house is a full-scale model replica of the “House of the Governor” at a Mayan site at Uxmal, and the third house is a “Mayan Revival Style” architecture inspired by Frank Lloyd Wright’s designs in Hollywood.

The man living in Mayan style is Dr. Lonnie Hammargren, a neurosurgeon, former Nevada Lieutenant Governor and Honorary Consul to Belize. The houses contain thousands of oddities from 65 years of collecting unusual things like an iron lung, a Batmobile, a Liberace staircase and Bugsy Siegel's toilet, even a fancy Easter egg entryway that Liberace once used for an Easter performance. Also on the premises are an Apollo Spacecraft Capsule, a Space Shuttle replica, and a Stonehenge reproduction.

Jason Wakefield of Top Ten Real Estate Deals explains why he ranked this one the weirdest: "Just beyond Evel Knievel's Messerschmitt motorcyle under the garage, the doctor has an authentic Egyptian tomb where he is to be buried and become part of the museum. The museum features a full pulley system for opening and closing the sarcophagus. Other unique characteristics include a Clark Gable dummy jumping out of a plane over an authentic "Welcome to Reno" sign, a dolphin tank from the original MGM casino, and if you look out the right window you will see the back of a Space Shuttle replica. The home is as unique as the Nevada history it exemplifies.

Mystery Castle

Location: Phoenix, Arizona


Price: Not on the market

Claim to Fame: Built by a man who abandoned his family and disappeared after learning he had tuberculosis

Boyce Luther Gulley left his Seattle office in 1927 and was not heard of until 3 years later in the hills south of Phoenix. There he spent the last 15 years of his life creating a three-story, 18-room mansion crenellated parapets, turrets, and a tower. Gulley constructed the castle from found and cheap materials like native stone and adobe bound by a mortar of sand, cement, calcium, and goat's milk. The house’s curious features include petroglyphs, automobile parts, Depression glass dishes as transoms, windows made from Gulley’s Stutz Bearcat, and the Bearcat’s windshield as a wall panel.

Gulley built stairs over a boulder so as not to disturb the landscape, and for the same reason he hauled natural materials from over a mile away. The wife and daughter he abandoned moved in after Gulley’s death in 1945, and began conducting tours. Daughter Mary Lou Gulley just died herself in November 2010.