At its most basic, organic architecture — a design philosophy envisioned and championed by Frank Lloyd Wright — promotes harmony between the built environment and its natural surroundings, whether it be a coastal landscape, a dense woodland, or a stark, primitive desert. In effect, the interior and exterior worlds meld into one as a unified whole; Mother Nature is embraced, brought closer to a home’s inhabitants; linearity and rigidness is eschewed and replaced with curves, waves and shapes often representative of the natural world. As design writer Eva Hagberg explains in "Nature Framed," a gorgeous book that profiles 24 boundary-blurring homes: "What these houses do is more than simply frame nature; they transform, viscerally, the relationship between and humans and the outside.”

In addition to classic works of organic architecture that grow from instead of disrupt the natural environment, there are some homes that crank the nature-home blurring aspect up a notch by closely mimicking the forms of nature that surround them, in many cases camouflaging the structures so that they almost completely disappear into the landscape. Wait … did that giant boulder we just drove by have windows?

Although the quantity of such homes is great, below we’ve rounded up nine of our favorites. Some take the classic approach to the concept of organic architecture and blend seamlessly into their natural surroundings while others, well, stick out a bit more.

The Pierre, Olson Kundig Architects

San Juan Islands, Wash. (2010)

The Pierre, Olson Kundig Architects, San Juan Islands, Wash.

Lauded Seattle-based architect Tom Kundig specializes in creating one-of-a-kind residences that melt harmoniously into their natural surroundings instead of clash with them. And after a quick glance at the exterior of this 2,200-square-foot weekend retreat in the beautiful San Juan Islands, you’ll fully understand why it's called The Pierre or “stone” in French: It’s actually built into a rock outcropping. Erecting this Flintstonian bunker was no easy task as Kundig equates the excavation process to “pulling the thread out of a sweater” in a New York Times T profile.

Reads the project description of the home, one that “almost fully disappears into nature” when viewed from certain angles: “To set the house deep into the site, portions of the rock outcropping were excavated using a combination of machine work and handwork. The contractor used large drills to set the outline of the building, then used dynamite, hydraulic chippers, a selection of wire saws and other hand tools, working with finer and finer implements as construction progressed. Excavated rock was re-used as crushed aggregate in the concrete flooring. Excavation marks were left exposed on all the stonework, a reminder of the building process.”

Casa do Penedo, architect unknown

Fafe Mountains, Portugal (1974)

What appears to be a masterful Photoshop job is, in reality, an honest-to-goodness country home carved from and wedged between four giant boulders in the Fafe Mountains of northern Portugal. Just ask the dozens of tourists who have made the pilgrimage to see the unbelievable structure with their own eyes. Casa do Penedo — or “House of Stone” — appears to almost completely blend into the natural environment — a craggy, remote hillside spotted with wind turbines — surrounding it. Inside the rustic abode, there’s stone furniture, a fireplace and log railings. Cozy! There’s even a swimming pool on the premises.

Given its status as an official tourist magnet and because of attempted break-ins and rampant vandalism, Casa do Penedo now sports not-so-Stone-Age bulletproof windows and a steel door. The home’s current owner, Vitor Rodrigues, has reportedly even decided to move out due to all of the rampant looky-looing.

Joshua Tree Boulder House, W. Garett Carlson

Joshua Tree, Calif.  (2009)

While it may not boast the true naturalistic cred of Portugal’s Casa do Penedo, you have to hand it to W. Garett Carlson, a Beverly Hills-based celebrity landscape architect, for resorting to truly inventive camouflaging techniques in the design of his Joshua Tree Boulder House. Situated on 2.5 acres in the middle of the desolate, boulder-strewn desert near California’s Joshua Tree National Park, the front façade of the 1,700-square-foot abode is obscured by, you guessed it, a giant faux boulder made from concrete.

Designed to “combine architecture and landscape architecture in a most harmonious way,” the eco-friendly desert retreat hit the market in 2010 for $1.35 million and was later reduced to $975,000. Check out the comprehensive video tour above, in which the narrator breaks out all the “M” words in the book — magical, majestic, modern, mysterious, mind-blowing, etc. — to describe the property.

Dick Clark “Flintstones” House, Phillip Jon Brown

Malibu, Calif. (build date unknown)

We don’t know a whole lot about the history of a certain Flintstonian mountaintop property in Malibu that’s currently on the market for $3.5 million and being billed, somewhat mysteriously, by its listing agent as a “Celebrity Romantic Retreat.” What we do know is that the curious cave-cum-crib — and the rugged, view-heavy 23 acres surrounding it — was owned by the late Dick Clark. The New Year's ball drop specialist put the one-bedroom novelty up for sale not too long before passing away at the age of 82 in April 2012.

And we’d like to think that the World’s Oldest Teenager initially set out determined to build a cave house in the mountains of Malibu, but apparently that’s not quite the case. Architect Phillip Jon Brown tells CNN that the home’s prehistoric design was “dictated by circumstances” due to objections from concerned neighbors: the Santa Monica Mountains National Recreation Area. “[Clark] dug in his heels and said he was going to build a house there. I came up with the idea that if the house looked like a rock formation, the park conservancy would let us build on top. They liked the concept.”

SeaSpace, Mark Mills

Carmel, Calif. (1969)

A breathtaking, rubberneck-inducing example of organic architecture from Frank Lloyd Wright disciple Mark Mills, the SeaSpace house at 62 Yankee Point Drive in Carmel, Calif., boasts three bedrooms, 3 1/2 bathrooms, spectacular ocean views and nary a right angle. The 2,267-square-foot home is also for sale, having been on the market for well over 200 days now with a price tag of nearly $3 million. In the video tour (above), the “undulating” property is described as a “space for a person who loves nature” by listing agent John Saar.

Dubbed by architecture writer Janey Bennett as one of the most “interesting and under-published” architects who served time at Wright’s Wisconsin studio, Taliesin, Mills’ love of the seashell form is believed to have been inspired by Wright himself, who called molluscan shelters “housing produced by god.”

Low Impact Woodland Home, Simon Dale

Camddwr, Wales (2005)

low-impact woodland house

With a small sampling of homes inspired directly and indirectly by Frank Lloyd Wright firmly covered in this list, we certainly wouldn’t want to neglect homes that take design cues from, umm, Middle Earth. And this one, a real honest to goodness Hobbit hole (minus the circular door) in the Welsh countryside, is a doozy.

Built by hand with minimal tools by impassioned permaculturist Simon Dale for less than $5,000, the self-described “Low Impact Woodland Home” is solar-powered, well-insulated and, last but not least, mortgage-free. Says Dale: “This sort of life is about living in harmony with both the natural world and ourselves, doing things simply and using appropriate levels of technology. These sort of low-cost, natural buildings have a place not only in their own sustainability, but also in their potential to provide affordable housing which allows people access to land and the opportunity to lead more simple, sustainable lives.”

Conch Shell House, Octavio Ocampo

Isla Mujeres, Mexico (build date unknown)

Conch Shell House, Isla Mujeres, Mexico

While Mexican artist Octavio Ocampo’s Casa Caracol — Conch Shell House — doesn’t exactly blend seamlessly into the natural environment like some of these other homes, you’ve got to hand it to him for really sticking with the nautical theme and running with it. Plus, he’s provided lost tourists with the ultimate in directional landmarks: Just take a left at the giant conch shell house on the corner and walk 50 meters.

Taking equal architectural cues from both SpongeBob SquarePants and Antoni Gaudí, Casa Caracol is made primarily from concrete but also incorporates a fair amount of reclaimed/recycled materials including seashells plucked from local beaches. Plus, the 5,500-square-foot abode — complete with stunning views of the Caribbean Ocean and a private swimming pool — is actually a vacation rental. Looking to live out your Princess Ariel fantasies? Book now!

Dragon Rock, Russel Wright

Garrison, N.Y. (1961)

Dragon Rock at Manitoba

Dragon Rock at Manitoga — the Garrison, N.Y., estate of Russel Wright, the highly influential industrial designer perhaps best known for his best-selling American Modern ceramic dishware — is a modernist retreat that’s nothing less than enchanting. Surrounded by a 75-acre woodland garden with an extensive network of meandering paths and water features, Dragon Rock was designed and built to coexist in harmony with nature. The land itself, purchased by Wright in the early 1940s, was severely damaged by years of quarrying and logging. Wright spent years nursing the landscape back to health while building his home/studio, a glassy, green-roofed box perched on a granite cliff above a quarry point that disappears into its dense arboreal surroundings. Writes architect Malcolm Holzman: “His [Wright’s] artistry was enhanced by the challenges of building with stone and timber, accentuating vistas, and bringing the manmade and natural environments together.”

Dragon Rock and the surrounding grounds of Manitoga (Algonquin for “Place of Great Spirit,” by the way) are open for public tours from May through October. Visitors should wear sturdy shoes and brace themselves for a 90-minute documentary narrated by Garrison Keillor. The estate gained National Historic Landmark status in 2006.

Fallingwater, Frank Lloyd Wright

Mill Run, Pa. (1937)

Naturally, we’ve included one of the most famous works — at least in the residential category, anyway — of the godfather of organic architecture, Frank Lloyd Wright. A bucket list-worthy home masterfully integrated into its natural surroundings — most famously, the 5,330-square-foot main house is partially built over a 30-foot waterfall — in rural southwestern Pennsylvania, Fallingwater was constructed as a weekend nature retreat for regional department store magnate Edgar J. Kaufmann and his family. We’re going to go out on a limb here and guess that Kaufmann is one of the only folks in modern history to have his country house featured on the cover of Time magazine.

Now maintained and operated by the Western Pennsylvania Conservancy, the iconic private home-turned-museum has received more than 4.5 million visitors since opening to the public in 1964. It was named a National Historic Landmark in 1966.

Related green architecture stories on MNN:

Click for photo credits

Photo credits:

Pierre: Benjamin Benschneider 

Woodland home:

Conch Shell House: notanyron/Flickr

Dragon Rock: pauletto/Flickr