Mile Square Regional Park is a park located in Fountain Valley, California. It includes two lakes, three 18-hole golf courses, archery range, baseball and softball fields, picnic shelters, and a 20-acre (81,000 m2) urban nature area planted with California native plants, a 55 acre (223,000 m²) recreation center with tennis courts, basketball courts, racquetball courts, a gymnasium, the Kingston Boys & Girls Club, and a community center.
The park derives its name from the near-perfect square of land that it occupies, bounded by Edinger and Warner Avenues on the north and south sides, and Brookhurst and Euclid Streets on the west and east sides, respectively. It measures one mile (1.6 km) on a side, for a total area of one square mile, or 640 acres (2.6 km2).(Wikipedia)