For decades, Natick natives have walked the halls and come of age in the old high school and although the new high school will be chock full of amenities and improvements, the old school will get a proper send off on Saturday. From 10 a.m. to 3 p.m., Memorial and Mahan fields will be the site of free family activities. A final pep rally is scheduled for 2 p.m., and the old building will be open for tours all day, with visitors having the opportunity to buy memorabilia from the school like bricks and lockers. At 7 p.m., Natick native Susan Wornick will emcee a goodbye gala that will include dancing, a DJ, and a meet and greet with Natick notables. Tickets to the gala are $40. Visit www.natickps.org for more information on the festivities.