Natural Tunnel State Park is located in Duffield, Virginia. The park features an 850 foot long and more than 10 story high natural tunnel carved out of the limestone mountainside. The park’s amphitheater is home to the Papa Joe Smiddy Mountain Music Festival held each Sunday of Labor Day weekend at 3 p.m. Visitors can also enjoy the Pickin’ in the Park series held on Sundays throughout the summer.