Inch Abbey is a ruined 12th Century Cistercian abbey just to the north of Downpatrick ad around 12 miles from Dundrum. The site of Inch Abbey was originally an island in the Quoile Marshes and was accessed by a walkway. Inch Abbey is open to the public all year round and can be accessed free of charge.
When coming through Downpatrick follow the directions to Belfast. You'll pass through a roundabout on the edge of town and shortly after see the Saint Patrick modern statue on the right. Not long after there is a turning on the left for Inch Abbey. This road is quite narrow and windy and a short way down there is a left turn, again signed Inch Abbey. This final stretch is even narrower and leads to a small car park just by Inch Abbey. When you head towards the ruins you can see Down Cathedral in the distance, just over the River Quoile.
Downpatrick Railway operates steam trains and old diesel trains on the short stretch from Downpatrick to Inch Abbey. The trains terminate at the edge of the road leading to Inch Abbey and it's only a short walk to Inch Abbey itself. Immediately at the termination point there is also a small play area that is useful to keep the little ones occupied whilst waiting for the train.