Rock Mill Park 3100 Kimball Bridge Rd, Alpharetta, GA30022 This park incorporates environementally friendly and sustainable features, according to the city's Web site and…More educational signs at the site. A green roof pavilion complete with ground level examples of this sustainable building feature educates visitors on a "green" way to help cool a building. It also controls runoff from a typical impervious surface, the roof of a building. An outdoor classroom is surrounded by examples of native plants suited for the climate and how wetlands help manage an ecosystem. Trails connect the park to the Big Creek Greenway.