For 10 days in May, one of Milan’s infamously unoccupied skyscrapers buzzed with new sounds and sights when thousands of artists, writers, and other creative types invaded the 31 floors to create a cultural common ground in the midst of the city.

The group renamed the tower MACAO and held nonstop talks, performances, and parties until the city evicted the occupiers on May 10, Nate Berg writes in The Atlantic Cities. (Also check out Vogue Italy’s photos from that day.) Berg quotes the press release from the MACAO occupiers, explaining why they decided to take over the empty building. Much like America’s Occupy movement, the MACAO group cites feelings of marginalization as one of the reasons they moved into the space.

We open MACAO in order to let the culture strongly regain a piece of Milan, in response to a story that too often has seen the city ravaged by public procurement professionals, unscrupulous building permits, in a neo-liberal logic that has always humiliated the inhabitants and pursued a single goal: the profit of few excluding the many.

The idea of public space is a loosely defined concept worldwide, but groups such as MACAO are forcing us to reexamine the notion. What is public space? That’s the question that, someday, we will have to answer.