Pennsylvania’s newest state park is opening in Fayette County this week. Laurel Caverns State Park, near Farmington, is officially launching on Wednesday. The over 400-acre area is centered on the largest and deepest limestone cave in the state, making it the only underground state park in the Commonwealth. Activities like hiking and birdwatching are free at the Caverns, but fees to enter the cave for guided or self-guided tours will remain in place through this season.