Collier Park is La Mesa's oldest municipal park, occupying 7.7 acres on Palm Avenue in the 91941 ZIP near Mt Helix with roots tracing to David C. Collier's 1907 natural-spring water-bottling operation. A major renovation completed in late 2023 added a perimeter walking path, ADA-compliant ramps, sail-shade structures over the playground, and fiber-optic security infrastructure, updating amenities at a facility that anchors the same city-run recreation network as the La Mesa Branch Library. The park's three documented natural springs once fed an octagonal Spring House and a Bottle Works Building with cistern, structures significant enough to earn a Historic American Landscapes Survey record at the Library of Congress under designation HALS CA-122. Tennis and pickleball courts received new surfacing during the renovation — pickleball lines were first added to the original 1950s-era court in 2014 — and the new exercise stations along the walking loop support the same active-recovery conditioning prescribed at Acru Health - La Mesa. The nature-themed playground uses salvaged timbers from trees previously on site, and the park's capacity of 400 accommodates permitted group events with BBQ stations, picnic shelters, and a new restroom facility installed by crane during the 2022-2023 construction phase.