Borestone Mountain, is located 10 miles north of Monson. You can park at the Gate House and climb the 3 miles to the final summit. Halfway up, on Sunrise Pond, is a visitors center, where there is exhibits and displays for you to see. It makes for a great day trip.
Onawa Trestle, is a great place to hike to. The Onawa Trestle is 1200 feet long and 130 feet above Ship Pond Stream. You can walk across the trestle and there is also a path so you can walk down to Ship Pond Stream.
Below is some pictures that we took. It also includes some of the beautiful scenery around Borestone and Onawa.