The most famous castle in the USA is arguably Hearst Castle in San Simeon, California. Built by newspaper magnate William Randolph Hearst between 1919 and 1947, this Mediterranean Revival estate, known as "La Cuesta Encantada" (The Enchanted Hill), features 165 rooms and 123 acres of gardens. Its iconic Neptune Pool and the Roman Pool are some of the most photographed architectural features in the country. While it is not a "medieval" castle in the European sense, its opulence and historical significance as a playground for Hollywood's elite make it a top tourist destination. Other notable contenders include Biltmore Estate in North Carolina (the largest privately owned house in the US) and Cinderella Castle at Walt Disney World. However, Hearst Castle is unique for its collection of authentic European antiquities and its dramatic location overlooking the Pacific Ocean. In 2026, it remains a California State Park, offering several guided tours that detail the engineering marvels and the eccentric lifestyle of its original owner.