To most, the words “National Park” provokes images of Yellowstone and Yosemite. The National Park Service (NPS) would like to broaden that image to include historic sites and notable open spaces within U.S. cities.

To celebrate its 100th anniversary, the NPS has partnered with the Washington, D.C.–based The Cultural Landscape Foundation (TCLF) to release a new guide to the historic and notable open spaces in Philadelphia.

The project is spearheaded by the Urban Agenda, an initiative within the NPS to make parks accessible and relevant to city dwellers. In addition to highlighting parks, plazas, and gardens, the online What’s Out There Cultural Landscapes Guide has entries for the neighborhoods, museums, homes, schools, and houses of worship that make Philadelphia Philadelphia.

The city’s book features over 50 significant sites, which users can filter by type, theme, style, or designer. Each entry has images and a written description of the site design and history.

Among many luminaries, the guide highlights the contributions of nineteenth century garden cemetery designer Philip M. Price, Thomas Holme, inventor of the Philadelphia Plan; and I.M. Pei, Louis Kahn, Robert Venturi, and Denise Scott Brown, 20th century architects who have contributed to Philadelphia’s built environment.

The guides build on TCLF’s What’s Out There database, which contains over 1,900 sites in the U.S. and Canada. Besides National Parks, the guide has information on National Historic Landmarks, National Natural Landmarks, National Heritage Areas, Land and Water Conservation Fund Sites, and National Register of Historic Places landscapes. TCLF already has non-NPS affiliated guides for Chicago, Denver, D.C., and Toronto, and over the next 18 months, the NPS and TCLF will release guides for Boston, New York, and Richmond, Virginia, Next City reports.