Master planned communities are large real estate developments covering a large number of acres that incorporate many different uses of land within the development. The communities are often primarily residential in nature, but often have commercial retail development, parks and green space, lakes, and community centers with activities such as tennis, swimming, or golf. These communities sometimes have "Over 55" sections within the community that cater to the active lifestyles of older adults. They may even offer other housing alternatives such as townhomes or condos or even multi-family housing within the development.