The three bedroom, two bathroom house became an instant icon when it was built in 1976 due to its unusual shape. It appears as a series of sprawling blobs perched in the hills over I-280 in Hillsborough.

The house was created by architect William Nicholson as an experiment in innovative building materials. The rounded forms are made by spraying a kind of concrete on metal frames molded over balloons. Most call it the Flintstone House, but it's also deemed the Barbapapa House after the circular, shape-shifting creatures featured in a children's book from the 1970s.

A Brief History of the “Flintstone House”

Coming Soon! Listed for $4,200,000 by Alain Pinel Realtors Burlingame.