Head to downtown Riverhead this Saturday, Dec. 2 at 1:30 p.m. for the 2nd Annual Tree Lighting and a day of holiday celebrations. The festivities will start at 1:30 p.m. with a Pet Parade. There will also be a holiday pop-up market at East End Arts and Santa will be at the Townsquare. A tree lighting caps off the day at 5 p.m.