Fly a drone over the city of Lafayette, California, and you might spot something resembling a spaceship plunked into a hillside.

It is here that Sheila Williamson and her husband made their home for four decades. The duo constructed the geometric manse by hand, spending seven scrupulous years calculating, cutting and painstakingly painting each piece of the three domes.

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“Just getting the permit was a bit of a challenge,” said Williamson, “because [the building department] had no idea what we were talking about.”

Eventually, the couple was able to get the city on board (enlisting the help of an engineer didn’t hurt, either). The result is a three-sphere, two-bedroom, two-bathroom home about 30 minutes outside of San Francisco.

The front entryway opens up into the main geodesic dome: a giant, warm, wood-paneled space containing an open kitchen, office, loft, and skylight.

Inspired by dome designs that were made popular by architect and inventor Buckminster Fuller, Williamson’s husband made the triangular panels himself, recycling pieces of wood from a nearby warehouse that had been torn down.

Neighborhood children pitched in to help, even hiding messages on the inside of some panels. If the home is ever dismantled, the hope is that people will still be able to read them, Williamson explained.

Fourteen triangle-shaped windows anchor the living room, providing an expansive view of the Reliez Valley below.

Up a short flight of stairs, two smaller geodesic domes contain the bedrooms, one of which has been converted into a laundry space in recent years.

The master bedroom features built-in wooden dressers and a geometric skylight. Outside, a deck offers a private nook for reading or taking in views of the landscape—often punctuated by deer, foxes, and quail.

Interacting with nature near the 1,700-square-foot home was always a favorite pastime for the family.

“It’s just the serenity, and it’s quiet at night. If you turn your back to the valley, you can see the stars,” Williamson said. “How often can you see the stars anymore? You can watch them progress across the sky over the year.”

With her children grown and gone, Williamson decided to put the home on the market. Her husband passed away last year, and she felt the space was too much for one person.

“It’s just a lovely place to sit out on the deck and watch the world go by,” she said. “It’s just really peaceful.”

Dina Del Monica of Pacific Union holds the listing.

Photos courtesy of Todd Taylor of Taylor Photography Group; Story written by Lindsay Cohen for Zillow