From the airport on the m50: On to the M50 heading southbound, continue along the motorway through the toll bridge until you see a sign for Ballinteer/Dundrum/Sandyford. This is Exit Number 13. Take the 2nd exit off the roundabout and continue straight ahead. Go through three roundabouts and you will have Tesco Petrol Station on your left. The next set of traffic lights is at a large crossroads. Here, take the right turn and go straight up the hill. Straight through one roundabout and we are up there on the right hand side. You will see a sign for the IMI.