The story of one of the most beloved campus landscapes in America as told by the designers and historians charged with its care William Penn envisioned Philadelphia as a "greene country towne." Perhaps nowhere has this ideal been realized more than the University of Pennsylvania campus. Indeed, the very meaning of Pennsylvania--"Penn's Woods"--alludes to this idea. Trees, especially, along with other plants, have played an essential role in establishing the character of the Penn campus in West Philadelphia from its inception onward. Indeed, Penn's urban campus achieved standards of professional practices deemed important for arboreta and botanic gardens in 2017 and was awarded a Level I Accreditation by The ArbNet Arboretum Accreditation Program. As an official arboretum, the campus contributes a botanical collection to the University's educational purpose. Penn's Sylvania analyzes and celebrates the development of the university as a green space, with noted landscape architects, designers, architectural historians, and photographers providing their perspectives on the campus and the specimens housed within.Renowned historian Witold Rybczynski traces the evolution of the campus idea from the tower to the green, while acclaimed landscape architect Laurie Olin highlights some of the memorable individuals responsible for greening Penn's campus. Catherine Seavitt explores the rich heritage of the pawpaw, a favorite species of the native people of the Philadelphia region, and Susan Weiler details the latest iteration of Woodland Walk, one of the campus's main arteries. Lara Roman, Theodore Eisenman, Robert Lundgren, and Chloe Cerwinka describe the coordinated efforts required to maintain an arboretum, and Ignacio F. Bunster-Ossa captures the landscape's defining features in his stunning photography. Illustrated by more than 75 of Bunster-Ossa's photographs as well as featuring archival drawings, blueprints, maps, plans, and diagrams, Penn's Sylvania not only showcases the critical importance of trees to Penn's urban campus but also introduces the people responsible for establishing and conserving its rich botanical heritage.