Furnished Apartments For Rent El Cajon . Search houses for rent in el cajon, ca. The city began as rancho el cajon in 1845, and the city was incorporated in 1912. 37 Furnished Apartments for Rent in San Diego, CA Westside Rentals from www.westsiderentals.com 1 el cajon furnished apartment for rent. Explore rentals by neighborhoods, schools, local guides and more on trulia! Start your free search for furnished apartments today.