CASTLETOWN, a parish, partly in the barony of LOWER, but chiefly in that of UPPER DUNDALK, county of LOUTH, and province of LEINSTER, 1 mile (N. W.) from Dundalk ; Containing 838 inhabitants. This place is situated on the bay of Dundalk, and on the roads leading respectively to Castle-Blayney and Armagh, which branch off near the village. It derived its name and most probably its origin from the erection of an ancient castle, which in 1318 was assaulted and partly destroyed by Edward Bruce, and which, after sustaining great injury during the parliamentary war, was finally surrendered to Cromwell. The castle occupies an eminence about a mile from Dundalk : the remains, which are nearly in a perfect state, consist of a large quadrangular massive pile, defended at two of the angles by small projecting square towers, and at the two opposite angles by similar towers of larger dimensions, all rising above the high pointed roof of the main building, and crowned with battlements, forming an object of very imposing character. Tradition says that it was a residence of Fingal : it subsequently belonged to the lords Bellew, whom the Boyne family succeeded ; and the present proprietor derives his title from a fee-farm grant made by Mr. Sibthorpe, trustee to the late Lord Boyne. The buildings are at present occupied only as offices of the modern mansion adjoining, which is the residence of J. Eastwood, Esq., who intends immediately to convert the castle into a residence. Near the demesne is the residence of Jacob C. Murphy, Esq. The parish comprises, according to the Ordnance survey, 26 10- statute acres, of which 2047- are in Upper and 563 in Lower Dundalk. The system of agriculture, though better than it was, is still capable of great improvement ; the gentlemen who cultivate their own lands have adopted the improved system, but many of the working farmers adhere to the ancient mode. There are some good quarries at Greenfield, from which stone is raised for building and mending the roads. The mountain streams of Philipstown, Dungooley, and Forkhill, unite in this parish, a little before their influx into the sea, forming the river of Casthetown, up which the tide flows nearly a mile, affording every facility of navigation.
It is a rectory and vicarage, in the diocese of Armagh, and forms part of the union of Dundalk : the tithes amount to £200. 6. 5-. In the churchyard are the ruins of an old chapel, which, from an inscription over the altar, appears to have been erected in 1631, by Sir Walter Bellew, Priest, in honour of St. John the Baptist. In the R. C. divisions it is part of the union or district of Dundalk. A national school has been built in the churchyard, and an infants' school is supported under the patronage of the rector, Mr. and Mrs. Eastwood, and Mr. Murphy. On the summit of the hill, on the brow of which the castle is situated, is a remarkable fort, forming a conspicuous object from the plains round Dundalk : in the centre is an extensive circular mount, having on the top a depressed surface, 460 feet in circumference, surrounded by an intrenchment with a high counterscarp on the outside. Adjoining this, on the east, is a quadrangular intrenchment, with a rampart, fosse, and counterscarp ; and on the west is a semicircular intrenchment similarly formed, but of smaller dimensions. These fortifications occupy the entire summit of the hill, and are prominently conspicuous for many miles around. Various lines of circumvallation may be traced around the castle ; and, on the plains below are the remains of a fort, little inferior to that on the summit of the hill, and the ruins of the old church or chapel, covered with ivy and presenting a picturesque object, in the cemetery, which is still used as a burial-ground. About a mile from the castle are the ruins of Balrichen castle, within half a mile of which are the remains of a singular fort, called Mount, or Moat Albani, situated near the small river Carrickasticken. The castle of Balrichen, or Balbriggan, which formerly belonged to one of the chiefs of the English pale, is situated on a gradual ascent between two winding rivers : it consisted of a lofty quadrangular tower, with a walled court-yard capable of containing a numerous retinue. Beyond this castle is the pleasant little promontory of Balrichen, between the rivers of Balrichen and Philipstown, which unite near this place. Various druidical remains are scattered over this promontory, the chief of which are a circle of five large upright stones on the summit of a hill, a cairn and several pillars, some detached, and some in groups. On an elevated piece of ground, called Carrickedmond, at no great distance from Balrichen, and near the Carrickasticken river, are numerous druidical relics, consisting of a temple of two concentric circles of large stones, with two smaller stones in the centre, two cairns, the foundations of a circular building, several small circles in which rude earthen kistvaens and human bones have been found, and detached upright stones, some of large size and probably monumental.