Holtwood Arboretum, also known as Holtwood Nature Preserve, is a 5,000-acre botanical preserve and recreation area in Holtwood, Pennsylvania. Open daily without charge, it brings together arboretum plantings, forest, wildflower areas, and sweeping views along the lower Susquehanna River, which shapes much of the landscape. Owned by PPL Corporation, the preserve supports hiking, picnicking, camping, fishing, hunting, and sightseeing. It is also notable for containing substantial fish ladders said to be the largest in the United States, as well as a museum of Native American artifacts.