The 'House of Stone' stands on a remote hillside in northern Portugal. Photo via flickr

It's a bit of a shame that the easiest way to describe this magnificent structure requires reference to a cartoon from the 1960s, but the way in which it incorporates its natural setting defies most conventional description. Located in the Fafe mountains of northern Portugal, A Casa do Penedo, or "the House of Stone," was built between four large boulders found on the site. Although the house may seem rustic, it is not lacking in amenities, which include a fireplace and a swimming pool--carved out of one of the large rocks. But, as word has spread, the sleepy little house has had visitors venturing to see it in droves.

The two-story home is built between four large boulders. Photos via Feliciano Guimarães

The house was built in 1974 as a family's rural retreat, but in recent years it has attracted the attention of tourists and architecture enthusiasts alike for being so perfectly integrated into its natural surroundings. Interest in the stone house has grown to the point that the current owner, Vitor Rodrigues, has had to move to find solace from the curious visitors.

For security, the house features bullet-proof windows and a steel door.

Because of the recent interest generated by the house and its remote location, Casa do Penedo has been the subject of robbery attempts and vandalism in recent years. Now, the house is equipped with bullet-proof windows and a steel door. Inside, however, the home is said to be quite cozy, with stone furniture, stairs, and railings made of logs.

The eco-friendly house has a view of wind-turbines on the Portuguese hillsides.

Recently, the house was the subject of a story in Portuguese media, which offers a peek into the home's interior:

While there may be no shortage of modern, eco-friendly design ideas being generated in the architectural community today, there's still something breathtakingly original about a house that looks straight out of the Stone Age.