Corona is a city in Riverside County, California, United States. As of the 2010 census, the city had a population of 152,374. Corona, founded at the height of the Southern California citrus boom in 1886, is advantageously situated at the upper end of the Santa Canyon, the only significant pass through the Santa Ana Mountains. South Corona is the newest and most upscale part of the city, and is located south of Ontario Avenue. Most housing stock was built between the early 2000s to the present, and ranges from suburban neighborhoods to custom built mansions in the foothills. This area has the highest rated schools in the city (as well as some of the highest in the region) and is known for being very clean, homogeneous, and well maintained. It is primarily upper-middle class and upper class income levels. The South Corona area includes the neighborhoods of Eagle Glen, Sycamore Creek, Trilogy, The Retreat, Dos Lagos, and Horsethief Canyon Ranch. The south Corona area also extends into west Corona.