During the third week in June every year, the Ascot Racecourse in Berkshire, England hosts a five-day Royal Ascot horseracing event. And what makes it royal? The Queen, of course! Queen Elizabeth and fellow royals attend every year, making the 300-year old spectacle a staple in the British social calendar. And a royal presence requires a specific dress code—attendees must wear formal attire and a hat or fascinator. The result? Well, the toppers are as creative as they are crazy. Check out 27 of the most memorable hats from this week's Royal Ascot in the gallery now! The event ends tomorrow, June 18th.