Ashford Castle Hotel is a trip into a history book. If you spend the night there, you're in pretty good company: this sprawling noble estate has been around for centuries, and has entertained visits from King George V and his wife Queen Mary, John Lennon, Oscar Wilde, Ronald Reagan, and John Wayne. The castle was built in 1228, replacing an even older monastery, and was converted into a hotel in the late 1930s. At one point, it was owned by the Guinness family (you know the one) who purchased the estate in the 1850s. Simply put, this is a massive medieval castle that has been renovated over the years to incorporate many architectural styles, contains extensive grounds and meticulously planted gardens, and is teeming with historical significance.