The University of California at Santa Barbara, the fourth largest in the UC system, is not actually located in Santa Barbara itself, but in a community a short drive north, in Santa Barbara's neighbor, Goleta. Goleta has just achieved its own cityhood. UCSB is a small city in itself, and most of the students live in the nextdoor community of Isla Vista. Spread out over 800 acres overlooking the ocean, the University is the single largest employer in Santa Barbara county. Goleta is also home to many of the electronics and research and development firms that flourish in the county. Goleta Beach has a salt marsh which is a good place to spot many species of ocean and beach birds, and a Monarch Butterfly preserve. The Witness Tree, located at 5555 Hollister Ave, is a historic 300 year old sycamore tree marking one of Santa Barbara's earliest homesteads.