Screwed to the front of a garage underneath a Boise-neighborhood foursquare, a small, shoebox-sized frame houses a trio of wood-mounted, painted rocks with faces that look straight out of a Hayao Miyazaki movie.

"Welcome to Portland's miniature museum," reads the sign at 3820 N Haight St., where Christopher Davies has been displaying art from friends—artists or not—for two years.

"I'm just trying to create my part of the cultural anthill," says Davies, who adds that he finds Portland's art scene lacking. The mini-museum is his answer to that, and also a bit of a poke in the ribs to a city that Davies—who also builds Renaissance-era musical instruments and hosts baroque concerts in his home—considers more obsessed with beer and food than art.

This, he says, is his way of adding a little bit of hidden art to the scene for people to discover. He says he loves seeing people stop outside to look at the displays—sometimes paintings, sometimes sculptures—and want more.

"People show up, and they look at it and say, 'Cool…when can we go to the museum?' This is the museum," he says, chuckling. "My greatest fear is they won't get the joke. It's a joke, but it's serious."