The Santa Ana Freeway is one of the principal freeways in Southern California, connecting Los Angeles and its southeastern suburbs including the freeway's namesake, the city of Santa Ana. The freeway begins at its junction with the San Diego Freeway (Interstate 405), called the El Toro Y, in Irvine, signed as Interstate 5. From there, it generally goes southeast to northwest to the East Los Angeles Interchange, where it takes the designation of U.S. Route 101.