There are lots of nice places to wander to in UCD, including some really nice wildlife areas parallel to the N11 if you follow the paths that way.. plus there's the really cool sculpture of the "Egg" - make sure you look inside - it's beautiful. (this is just up from the lake on the O'Reilly Hall side).
If it is raining, then I suggest you pop into one of the buildings or take shelter somewhere! There is a pub across the N11, Lonnegan's which is part of the Montrose Hotel. This is a nice spot for coffees/sketching if the weather is bad also. If weather is nice, takeaway coffee is available in the Centra - over beside the student residences, beyond the bus stops towards the Foster's Avenue entrance.
Get the Number 10 bus to be dropped inside the campus, or the number 46a to be dropped at the far side of the fly-over in front of the Montrose Hotel.
I'm not sure if I'll be there myself yet, Cork are playing in the Semi-Final so I will probably be jumping up and down shouting at a tv somewhere :)
Enjoy! All new sketchers welcome - please just have a sketchpad in your hand so all will recognise you ;)
ps. HERE'S a link to some of the campus artwork, which is nice - plus some info on Noah's Egg :)