The Pine Hills in Plymouth offer a different experience from most of the riding south of Boston and on Cape Cod. The trails, which are mostly singletracks, claw their way through the woods dodging large rocks as they make their way up and down a series of short hills bisected by Route 3A.
Parking is at the Cleft Rock Parking lot located almost directly across the street from Serious Cycles. I'll divide this report into two parts as the trails on either side of the road differ greatly.
North of 3A the trails are commonly referred to as the 'Nuclear Trails'. That's because they are located behind the Pilgrim Nuclear Power Plant. The trails are on power plant property and exist as a public service of the power plant. Some of these trails are quite difficult. Occasionally you'll encounter structures that will add to your riding experience. While the trails are enjoyable they rarely meet the 'buffed singletrack' description so common in Plymouth and on the Cape. After a couple of rides you'll learn which direction of travel is the most fun. North of Route 3A you can expect to find about 12 miles of trails.
South of 3A the trails are more difficult. Branching off from a few old logging roads you find an extensive network of motorcycle trails. These singletracks seemingly go up and down every short hill in the woods. Occasionally they are too sandy or steep to ride, necessitating a few very short walks, but for the most part they are negotiable. Most riders will follow these trails in a westerly direction. That is to say descending, mostly, until they encounter Beaver Dam or Old Sandwich Road from where they'll choose to ride back to the top on pavement or one of the old doubletracks. I have done these trails in both directions and when I do I mostly avoid the singletracks on the way back to the top.
The Open Street Map above shows many of the trails on both sides of Route 3A, but by no means all of them.
You’ll enjoy these trails. They’re challenging and a pleasant change from the ‘coastal plain’ that makes up most of the Southeastern end of Plymouth County.