Kennywood is an amusement park located in West Mifflin, Pennsylvania. The park first opened as a "trolley park" attraction at the end of the Mellon family's Monongahela Street Railway on May 30, 1899. It was purchased in 1906 by F. W. Henninger and Andrew McSwigan who later formed the Kennywood Entertainment Company, which owned and operated the park as a closely held family business for over 100 years. Kennywood was purchased by California-based Palace Entertainment in 2007. The amusement park features various structures and rides dating back to the early 1900s. Along with Rye Playland Park, it is one of only two amusement parks listed in the National Register of Historic Places.