“In the shoulder seasons, sometimes our public spaces can look a bit a bit drab,” said Aaron Greiner, executive director of CultureHouse, the Somerville-based group behind the project. “So we thought, what could encourage people to be out of their home, meet a neighbor, have a conversation, and bring some color and light to our daily lives?”

The result is City Greens, a project they hope will some day include as many as nine holes in other public spaces around Somerville, Cambridge, and Boston becoming a sort of diffuse mini golf course built into the urban environment of the three cities.

Culture House Operations Manager Phoebe Wong.Finn Gomez for the Boston Globe

To test out the concept, they built and paid for the first one themselves and, with a city permit, plunked it in Union Square, on Somerville Avenue.

It comprises a few square feet of turf with some obstacles. In a bucket, a trio of putters and an array of golf balls are available for anyone to use, night or day.

The hole’s centerpiece is a miniature triple-decker, which has PVC pipes inside that lead to a hole.

Culture House Operations Manager Phoebe Wong and Executive Director Aaron Greiner with their pop-up mini-golf hole in Union Square, which they hope is the first of many.Finn Gomez for the Boston Globe

Players can launch a ball up one of two ramps toward this chest-high structure. Hitting it into the porch on the second floor, per the instructions, saves you one stroke. Firing it onto the top porch saves you two.

Or, you can simply hit the ball through an opening in the building’s basement — in the parlance of some local real estate brokers, the “garden level” — for the fastest route to the cup.

CultureHouse fabricated the hole themselves, making it out of nautical-grade plywood so it can withstand the elements.

It’s certainly a conversation starter, which its creators said is the point.

Housing is perhaps the most hotly debated topic in Somerville these days, as rents continue to climb, and as the city’s residents weigh the merits of projects like a 26-story residential tower in Davis Square

In a market like this one, the jokes practically write themselves about what a mini-golf-sized apartment would fetch were it up for rent.

So CultureHouse staff said they were thrilled when they saw that the first big splash the pop-up made online came in the form of a tongue-in-cheek real estate listing.

“1BR luxury microunit for rent in the heart of Union Square! Spacious (1k sq inch), MultiBalcony and UnderMarket $4800,” one person wrote in post on social media that included pictures of the City Greens project and garnered lots of attention online. “PRIVATE GOLF COURSE INCLUDED!”

Beyond the sky-high cost of living in Somerville, the mini-golf hole’s creators also hope to get people to reflect on the region’s architectural heritage, and the widely shared experience in the Boston area of spending at least part of your life in one of these three-story buildings.

“The triple decker is historically significant, and a very important part of what makes Somerville Somerville,” said Yilan Sun, the nonprofit’s urban design lead. “It’s a local commentary on what it means to live here.”

Another perk of this triple-decker that you don’t often get with the real thing, she noted, is that you can thwack golf balls against it as many times as you want, without catching hell from your landlord.

“You’re not gonna lose your security deposit,” Sun said, with a laugh.

A placard on the side of the mini-golf hole indicates it’s a “par 3.”Finn Gomez for the Boston Globe

Spencer Buell can be reached at spencer.buell@globe.com. Follow him @SpencerBuell.