Waterstone at Wellesley will host a holiday open house and social gathering on Thursday, Dec. 6 at 4:30 p.m. This event is free and open to the public, but an RSVP is required. Call 781-235-1614 to RSVP. Waterstone is located at 27 Washington St., and includes 134 apartments for seniors 62 and older. It features independent and assisted living rental apartments. For more information, call 781-235-1614.