Main location at Lake Avenue, from 9 a.m. to 2 p.m. Woburn Lodge of Elks to host Fishing Derby and Cookout. Other activities include spin art with the Middlesex Lions, kayaking, T-shirts, the premiere of the film “The nature of Horn Pond” by Philip Valende and the first SCI concert of the season featuring the Austin Torpedoes at 5 p.m..