Explore historical, cultural, heritage and medieval sites. A chance to see Royal Windsor Castle, Windsor Castle, the largest and oldest occupied castle in the world, is the home of Her Majesty Queen Elizabeth II. Stepped in history, Windsor Castle perches proudly on a lush wooded hill overlooking the Thames. Dating back to Norman times, with sweeping landscaped gardens and turreted Round Tower, it’s easy to see why it’s the Queen’s favorite weekend residence royal Windsor.