Welkinweir is a 197-acre (80 ha) nonprofit arboretum, garden, mansion, and conservation area located at 1368 Prizer Road, East Nantmeal Township, Pennsylvania, United States, near Pottstown. It is part of the Hopewell Big Woods. It is open to the public daily without charge. Its arboretum includes cherry, dogwood, dwarf evergreens, franklinia, magnolia, Japanese maple, swamp and sugar maple, and sweetgum, as well as azaleas and rhododendrons.