Journey back in time by almost 1,000 years as you enter Christ Church Cathedral, Dublin. Built circa 1028, the sacred monument is perfectly located in the heart of the city's medieval center and features a beautiful interior and the largest crypt in Ireland. Constructed in the early 12th century, and the oldest structure still in use in Dublin today, the crypt is home to some fascinating memorials and curiosities. Look at the treasury, and see the mummified cat and rat. According to cathedral lore, the cat chased the rat into the pipe of an organ and both became stuck. They are mentioned by James Joyce in "Finnegans Wake" and are known locally - with typical Dublin wit - as "Tom and Jerry." Follow in the footsteps of the pilgrims who beat a path to the church in the Middle Ages. Learn about the important collection of relics in the church. Admire the stained glass windows and medieval floor tiles of the nave.