The place which became Wompatuck State Park was originally developed to house a World War II munitions depot! After the war a large portion of this depot was returned to MA— and turned into a state park.
“Wompy” as it is often called, is roughly the shape of a diamond, and is cut into North and South sections by Union St., the main road in the park. The campground and a great concentration of trails are in the SW portion of the park.
Another great concentration of trails surrounds the Aaron River Reservoir, in the NE part of the park. Two nice additions you might not find at most state parks are the copious paved roads (closed to cars, mostly) that can help you if you lose your way, and the paved bike trail inside the park, which could work for less “gnarly” family members.
(Portions of this history of the park come from Bill Boles)