Every 30 minutes in a grassy stretch of Calistoga, an underground river grows restless. The water, heated by magma far below the earth's surface, boils and rises through fissures in the ground. When it reaches the open air, it shoots upward in a towering spigot—up to 100 feet high. This display is known as the Old Faithful Geyser of California, a natural wonder that shares the title of "old faithful" with only two other geysers in the world due to their dependable schedule. A picnic ground at the geyser site allows guests to eat lunch against panoramic views of the Pacific Palisades and Mount Saint Helena. While they wait for the next eruption, visitors can greet the on-site petting zoo's animals—guard llamas, Jacob's four-horned sheep, and Tennessee Fainting Goats, named for their tendency to fall over and fan themselves when startled.