PLAZA HALL  was built to be the offices for the county seat when San Benito County withdrew from Monterey County, but politics, the railroad, and eventually businesses left San Juan out after 1870.  Plaza Hall then became home to the Zanetta Family until it was purchased along with other buildings and the Plaza grounds up to the Arcade of the Mission itself by the State of California for  $66,000 in 1933.  The Fireman’s Ball was held there every year since 1856.  The Plaza History Association sponsors a Victorian Ball there each June. 45,000 4th graders visit the Park each year.