(Bring your own horse): Nice, easy, flat main trails with off-main-trail paths, that’s close to Nashua, Hudson, Pelham. It’s at the junction where the three Mass. towns meet, just over the NH/Mass. state line. For horses, be aware that this forest disallows ATVs BUT the ATV folk can be known to persist illegally. Just saying, in case your horse has ATV spookiness. This pocket of forest land spans about 1100 acres of walking/hiking paths, granite outcroppings, ponds and wetlands. It was likely the site of a Native American village before colonial settlement. There are 6 miles of trails, both on and off main path used for hiking, biking, horses and in winter, XC skiing and snowmobiling. No facilities that we found. A pretty place where the main paths feel public enough, off main paths can feel pretty remote. We loved the main trails for season-start conditioning, but the off-trail paths are fun too, I’d just caution to stay out of off-trail bogs because Cloud sank into one knee deep and it was looking a tad challenging there for a minute.
Official parking lot is on Trotting Park Road just north of Varnum Ave. in Lowell, MA but we did not park there, so if hauling a horse trailer, you are strongly urged to get exact directions for parking in advance by calling them.