High Quality Content by WIKIPEDIA articles! Valencia High School in Placentia, California, was established in 1933. The high school originally shared buildings with Bradford Avenue Elementary School until 1964, when Bradford Elementary closed and Valencia High School became the sole occupant of the campus property. Until 1967, when El Dorado High School was built, Valencia was Placentia's only high school. Valencia High School is located at 33.87622,-117.86929. Many of Valencia's buildings, including the auditorium and cafeteria, were built during the Depression by the WPA.