If you venture just over 30 miles down the Potomac River from Washington, D.C., you'll reach a state park steeped in American history and outdoor recreation. Smallwood State Park, which spans nearly 630 acres, boasts a prominent perch where the Potomac River meets Mattawoman Creek. The Smallwoods owned the land until the mid-19th century, and Smallwood State Park was later founded in 1957. Today, visitors come to this under-the-radar state park for a wide range of outdoor adventures, including hiking on nature trails, fishing, and launching a canoe from the park's marina to explore the Potomac River. Smallwood State Park is open until sunset year-round, though opening hours depend on the season, and admission starts at $3 per person and vehicle as of this writing.