Vast salt marshes once covered most of East Boston and the Dorchester shoreline, meadows dotted the hilltops of Roxbury, and pristine streams coursed through the forests of Hyde Park and West Roxbury. Although almost all significant portions of these habitats have been lost due to extensive human-induced manipulation of land and water, remnants of these original ecosystems - urban wilds - still dot the landscape and provide brief glimpses of the natural world. They harbor native plants and animals and perform a wealth of ecological services, such as storing floodwater, producing oxygen, and filtering stormwater run-off. They offer refuge from hectic city streets and serve as outdoor classrooms for children and adults learning about nature. By expanding the range of landscape experiences beyond that of the dense built environment and manicured Boston parkland, urban wilds form an essential part of the city's open space system.