The Derry Session House is located on the grounds of Derry Presbyterian Church in Derry Township. The 1 story log building is lapped with horizontal wood boards and was constructed circa 1732. Derry Presbyterian Church was founded by the area’s earliest settlers, Scots-Irish immigrants and traces its beginnings to 1724. The session house was constructed as a building used to conduct church business such as meetings between the pastor and elders. It also served as the church Sunday school and pastor’s office. During the week, the building was used as a school and in 1858 it began a two year tenure as the community’s post office. Little is known about the building’s use from 1860 until 1929, when Milton S. Hershey, founder of Hershey Chocolate, funded the erection of a glass enclosure to protect the building from further deterioration. Designed of glass and steel with a slate roof, and built by area architect and engineer D. Paul Witmer, the enclosure is ventilated and offers the fragile log structure adequate protection from the elements without obscuring it from public view. The enclosure was refurbished in 1999.