Since it was built in the early Christian era, it is associated with the times immediately after those of St. Patrick, thus making it significant for the Irish. This cashel is situated between Castlewellan and Kilcoo, overlooking Lough Reavy. In spite of its inconvenient location, people drive from south-west of Castlewallen, through a minor road off the A25 to Rathfriland to visit this site. Oval in shape, the site is quite similar to a rath or ringfort and has an accessible southterrain, which is a prominent feature of this site.
The size of the cashel is 40×33 m, with the average height of the walls being 8.2 ft or 2.75 m, with 10.8 ft or 3.3 m thickness. A notable recess can be seen just before its entrance on the left side, while the right side has a passage that leads to the modern entrance of the cashel. In the centre are stones that may be remains of a dwelling, while the T-shaped entrance to the southterrain is located on west of the centre. The circular wall is made of smooth drystone, just like the underground passages and rooms, even though the wall core is made of pebbles. It is assumed that the rooms would have been a haven for people and livestock during the times it was still in use. Though almost 1500 years old, some of the parts of this site are thought be made recently, such as the main entrance in the east or that of the southterrain. The new entrance is located near the main road, while the one situated on the east and equipped with a farm gate is thought to be the original one.
The southterrain is 15 m in length and 2.1 m in height, and comprises a rectangular chamber alongside the original and narrower entrance. Its roof is lintelled, though some lintels have been cemented in the restoration process, while the walls are completely made of drystone. This entrance is located exactly opposite the newer one, which is much wider than its older counterpart. It is assumed that the southterrain, or underground stone tunnel, was used for cold storage purposes between 5th and 11th century. Another feasible use of the southterrain is a hideout for Vikings who thronged these lands centuries ago. It is also possible that the residents built this structure to safeguard themselves from raids conducted by rival tribes and Vikings.