(Maryland)
Rosaryville State Park is a public recreation area with historical features located three miles southeast of Joint Base Andrews in Rosaryville, Prince George's County, Maryland. The state park includes the restored Mount Airy Mansion, which was formerly operated as an event facility, as well as hiking, biking and equestrian trails for day-use. (Ref: https://en.wikipedia.org/wiki/Rosaryville_State_Park)