On a self-guided nature walk, discover friendly garden gnomes hidden among the beautiful trees at Polly Hill Arboretum. You can pick up a brochure of clues and a guide to winter trees from a stand near the visitor center, and then set off on an adventure. The magical grounds are open daily from sunrise to sunset, but the gnomes are only visiting through the end of March. For details, check pollyhillarboretum.org or call 508-693-9426.