Which publishing mogul built a huge castle at San Simeon, California?

William Randolph Hearst is the correct answer because he was the renowned publishing mogul who constructed the opulent Hearst Castle at San Simeon, California. Built in the early 20th century, the castle served as Hearst's private residence and is known for its grand architecture, extensive art collection, and beautiful gardens. Hearst's wealth derived from his successful newspaper empire, and he used his fortune to create this extravagant estate, showcasing his love for art and luxury. The castle has become a significant historical and architectural landmark, attracting numerous visitors interested in its lavish design and Hearst's legacy in media and publishing.