The Slieve Donard and Millstone Mountain Loop from Newcastle is a 9.3 km looped trail that starts and ends in Newcastle, County Down, Northern Ireland. Based on our data, the trail is graded as Medium. For information on how we grade trails, please click here. Also, check our latest community posts for trail updates.This trail can be completed in approx 4 hrs 24 mins. Caution is advised on trail times as this depends on multiple variables. For more info, click here.Photo Credit :Albert Bridge