springs into bathtubs or drinking fountains. A very early 20th century advertising brochure listing the names of eleven physicians suggested: "...a remarkable spring furnishing a mixture of sulphur, magnesia, and arsenic, which has been found very beneficial in cases of rheumatism, Bright's disease, and other kidney and stomach troubles and malarial affections." Through those years and as late as the 1970s, the park featured a natatorium (a huge, indoor swimming pool filled with heated sulfur water), dozens of private heated mineral baths that visitors could rent, a restaurant, and various other buildings. Many of the springs were enclosed in stonework grottos, and stone bridges were built across the creek. Due to overuse, some of the springs became extinct, and surviving ones became very weak, producing very little output. Alum Rock Falls Road Private residents have access to the publicly-owned road. They enter the park and continue on to the rear parking lot. At the end of the parking lot is a metal gate which requires a security code number to continue on the public road. Visitors can also walk up the road, but there are various signs which indicate no trespassing. Fork in the creek Penitencia Creek has two main sources which converge at the "horse bridge" near the uphill end of the creek trail. The fork from the north is Penitencia and originates from Cherry Flat Reservoir. Alum Rock Falls is within the park but the City of San Jose has marked this part of the park as off limits since the 1980s. The creek from the south is Arroyo Aguague and originates in Grant Ranch. Although a couple miles of this lush canyon are within the park, this area too is off limits to visitors. Youth Science Institute Opened in 1953, the Youth Science Institute - Alum Rock Science and Nature Center, operated by the Youth Science Institute, features natural history exhibits and a collection of live teaching animals, including several injured and non-releasable hawks and owls that are found in the region. The center offers nature and science school and group programs, after-school science and summer camp programs. Animals that are commonly found throughout the park are displayed in the center. There is an exhibit of taxidermy birds that is sectioned off into owls, hawks, seabirds, and waterfowl. Animal remains are set up throughout the center and labeled accordingly. There is a separate room for live animals