Placentia is a city in North Orange County.  It was founded in 1910 and later incorporated in 1926.  Between 1960 and 1970 the population of Placentia boomed from 5000 residentes to over 25,000 residents.  The population is estimated at just under 55,000 in 2010.

Placentia is mostly defined by 1960s and 70s tract neighborhoods.  If has a small commercial and industrial center along the railroad corridor.  The architecture of Placentia reflects mostly mid-late century residential ranch style tract design with a few older craftsman homes from earlier settlement.  The commercial center has a few older store front buildings and industrial buildings.