From Lowell, MA:

Follow Rt. 495 South towards Marlboro/Worcester. Take Exit 31 (Route 119/Groton/Littleton Common). From the off-ramp, take a left on Great Rd. In approximately 2.1 miles, merge into Rt. 225 (Boston Rd.), which becomes Rt. 119/225. Follow 119/225 past Rt. 40 (Lowell Rd.). Bear left at the next fork in the road (stay on Main St./Rt. 119). At the next fork in the road, bear right. Follow Main St. past Champney St. to your right. Just past Champney St. will be the Groton-Dunstable Regional Middle School.

From Nashua, NH:

Follow Rt. 111 West (W. Hollis St.). W. Hollis St. becomes Runnels Bridge Rd. Stay on Runnels Bridge Rd. (still Rt. 111) until you cross the border into Massachusetts. Rt. 111/Runnels Bridge Rd. becomes Rt. 111/Nashua Rd. Follow Nashua Rd. until it ends and then take a left on Hollis St. (still Rt. 111). Cross Main St. (Rt. 113). Stay on Rt. 111 (now called River Rd.) until it ends. Take a left on Rt. 119/111 (South Rd.). Cross Fitch Bridge Road and continue on Rt. 119/111 (now called Main St.). Approximately 1 mile up on the left will be the Groton-Dunstable Regional Middle School.