No trip to Dublin is complete without looking around one of its oldest structures. Founded in 1592, Trinity was built during the 16th and 17th centuries and includes Jonathan Swift and Wolfe Tone in its alumni. It's well worth taking a stroll around Front Square, dropping into The Buttery for a snack. Indeed some of the college's older dining rooms are available to reserve for small or large parties and ensure a truly authentic experience.
Stroll along the cricket green and maybe join the students in The Pavilion for a pint. Both the Old Library and The Book of Kells are housed on the grounds but if you're looking for some cost effective sight seeing then head into the Science Gallery near the Pearse Street entrance where you'll have the chance to see a free, educational exhibition. Overall though, just taking a walk around the grounds will give you plenty to look at and admire.