Six Flags Magic Mountain, formerly known and colloquially referred to as simply Magic Mountain, is a 209-acre (85 ha) amusement park located in unincorporated Los Angeles County, just outside Santa Clarita, California, United States, 35 miles (56 km) northwest of downtown Los Angeles. It opened on May 29, 1971, as a development of the Newhall Land and Farming Company and Sea World Inc. In 1979, Six Flags purchased the park and added "Six Flags" to the park's name.