Every wonder about the bricks on the Red Trail, the springhouse on the Yellow Trail, or that fireplace in the middle of the woods? This class will answer those questions as you as you walk the trails and learn about 100 years of Thorncrag Nature Sanctuary history. Attendees should be able to walk a mile with some being uphill. The sanctuary is located at 360 Montello Street, Lewiston. Dogs are not allowed. Rain date is October 15th.