The first and most prestigious campus of the acclaimed University of California system, UC Berkeley is noteworthy for its varied architecture and profuse landscaping, its outstanding museums and research collections, its notoriety in the 1960s and 70s as a hotbed of student activism, and its myriad contributions to human knowledge, especially in the field of nuclear physics. Though the campus totals 1,232 acres and stretches high into the Berkeley Hills, the developed core of the university lies in the 178 acres situated along the north and south forks of picturesque Strawberry Creek. Sather Gate (1910), a filigreed wrought-iron and stone portal, fronts Sproul Plaza, a main gathering area for students. Sather Tower, or the Campanile, is the campus' signature structure. Modeled after the bell tower in Venice's St. Mark's Square, the 307ft, steel-framed, granite-clad shaft (1917) is crowned by a quartet of obelisks surmounted with bronze urns, and a soaring central spire capped by a bronze lantern. Its eighth-floor open-air observation platform offers panoramic views (open year-round Mon-Fri 10am-4pm, Sat 10am-5pm & Sun 10am-1:30pm & 3-5pm; closed Dec 25-Jan 1; $2).