DENN, a parish, partly in the barony of CASTLERAHAN, and partly in that of CLONMAHON, but chiefly in the barony of UPPER LOUGHTEE, county of CAVAN, and province of Ulster, 5- miles (S. by E.) from Cavan, on the road to Ballyjainesduff; containing 5915 inhabitants. It comprises, according to the Ordnance survey, 11,600- statute acres (including 125- acres under water), of which 7774- are in Upper Loughtee, 2113- in Clonmahon, and 1712 in Castlerahan ; 11,237 are applotted under the tithe act. Within the last few years, five townlands have been separated from it, forming, together with portions of three other parishes, the benefice and perpetual curacy of Ballyjamesduff. There are about 20 acres of woodland, and 500 of bog ; the remainder is good arable and pasture land. In the northern part of the parish is the mountain of Slieve Glagh, 1050 feet above the level of the sea ; and in the south-western part is that of Ardkilmore, 878 feet high. Fairs are held at Cross-keys, on Jan. 12th and March 17th, for general farming stock. The living is a vicarage, in the diocese of Kilinore, and in the patronage of the Bishop ; the rectory is impropriate in the Marquess of Westmeath. The tithes amount to £375, of which £150 is payable to the impropriator, and the remainder to the vicar, The glebe-house was erected by aid of a loan of £618 from the late Board of First Fruits, in 1817 : the glebe comprises 151 acres. The church, a neat small edifice, was rebuilt by aid of a loan of £600 from the same Board, in 1812. The R. C. parish is co-extensive with that of the Established Church ; there are two chapels, one in the townland of Drumavaddey, and one at Cross-keys, both small buildings, and the latter old and dilapidated. In the parochial school are about 50 boys and 20 girls ; and there are five pay schools, in which are about 220 boys and 70 girls.