"New parks can sprout up in the unlikeliest places. Low-income, inner-city communities are characterized by hardscapes – asphalt surfaces. When a community organizes and creates a plan for a new park, local governments can respond and purchase asphalt-covered areas like parking lots and transform them into public community parks. The average neighborhood park can run into the millions, but including a park budget in the initial master plan helps ensure local governments will finance it, and even partner with developers, local foundations, or conservancies to get it built. These types of projects can also come about if they are part of broader public-private urban redevelopment schemes aimed at providing housing, improving access to transit, and investing in the local environment."
Transportation infrastructure like old parking lots can provide convertible spaces for new parks, according to this post from Planet Forward.