If your kids are Harry Potter fans, this is the perfect place to take them. The Old Library in Trinity College (think Irish Ivy League University) has to be seen to be believed with its stacks of ancient tomes and bookshelves that seem to stretch for miles. While you're there, be sure to take a gander at the Book of Kells, which is included in the tour. This ornate manuscript was hand-painted by monks in the ninth century.