Inside the Trinity College campus, is The Book of Kells exhibition. The Book of Kells is a ninth century manuscript of the four gospels. Before seeing the manuscript itself, there is a detailed exhibition, which includes all the history and meaning behind it, as well as the process by which it was made.
Beyond the Book of Kells, up the stairs, you can find the Old Library, known as The Long Room. It is 65 metres long and filled with 200,000 gorgeous antique books. This was honestly one of my favourite places we went to. I could have stayed here for hours, and took a ton of pictures!