Harry Griffen Park is the largest park within La Mesa's city limits, spanning 53 acres at 9550 Milden Street in the Grossmont Summit area where La Mesa and El Cajon adjoin. The park's landscaped amphitheater seats 360 guests on concrete bleachers and hosts the city's free Sundays at Six summer concert series each June and July—a venue also available for weddings and graduations through the same permit system used for Nan Couts Cottage elsewhere in La Mesa. Canine Corners, the park's fenced dog run, provides three separate enclosures for small, medium, and large dogs, maintained by volunteers and supported by the La Mesa Park and Recreation Foundation. Additional facilities include a jogging path, horseshoe pits, eucalyptus-shaded picnic areas with barbecue grills, baseball diamonds, and a children's playground with slides and swings. Dog owners along the Lake Murray and Grossmont corridors pair Canine Corners visits with supply runs to Paw Country, one of East County's independent pet retailers. The 53-acre footprint requires multi-zone irrigation management, amphitheater AV infrastructure for concert production, volunteer-staffed dog-run maintenance schedules, and turf-rotation protocols across ball fields that serve Little League, adult softball, and soccer leagues simultaneously.