Home of numerous landmarks like Pleasanton Race Track and Hearst Ranch, Pleasanton claims the 260-acre fairgrounds that host the Alameda County Fair each year. In spite of massive growth in many sectors over recent years, the city has managed to preserve the small-town charm mirrored in the gateway "Pleasanton" arch and the historic Pleasanton Hotel and Cheese Factory buildings. Traditional shops and long-established services harmonize with modern development like the Hacienda Business Park developed by the Prudential Company and the Callahan Property Company. Over 875 acres provide 4.8 million square feet of office space for over 240 companies, making this one of Northern California's largest business parks. Stoneridge Mall opened its doors in 1980, featuring 160 stores that contribute substantially to the diverse tax base. Other amenities that are available to Pleasanton residents include the Castlewood Country Club, a golf course, community centers, senior center, Amador Theater Performing Arts Center, Cultural Arts Center, Aquatic Center, and parks filled with recreational amenities. Among the regional parks are the 3,000-acre Pleasanton Ridgelands Regional Park and the Shadow Cliffs Recreation area, popular for its Rapid Water Slides and opportunities for fishing, swimming, and picnicking. Known as the Jewel of Amador Valley," Pleasanton offers lush rolling hills, a warm community spirit, attractive housing options, and convenient rapid-transit connections to major Bay Area employment centers.