LETTERKENNY, about 25 m. N.E. of Donnegal, and 15 m. W.N.W. of Londonderry, forms a good station for visiting the wild scenery towards the coast. At Ards Castle, see ruins of Castle and Baltimore Ch. Dunfanaghy has some castellated ruins in its vicinity. At Hornhead, 28 m. W. from Letterkenny, see a remarkable cavern called Mac Swine's Gun, on a rocky cliff 60 feet perpendicular. Of these rocks the lower stratum is porous sandstone, hollowed into a cavern by the violence and continual buffeting of the waves, from whence an aperture proceeds to the summit. When the wind comes from the N.W. the billows being driven with great violence into the cavern, the water thus forced to find a passage through the aperture, rises to the summit of the funnel, from whence it again descends with a most tremendous noise. Near this is MacSwine's Castle, an ancient edifice, now fitted up as a modern residence. See Rutland, a modern fishing-town, worthy the notice of the statistical tourist. Kilmacrenan, about 8 m. N., has some ecclesiastical ruins, founded by St. Columb, of which the parish Ch. forms a part. See the rock on which the O'Donnels, princes of Tyrconnel, were always inaugurated; also Lough Salt, in a romantic situation on the summit of a mountain. Murkish Mountain, situated within 4 m. of two deep and safe harbours, Dunfanaghy and Sheephaven, affords siliceous sand in great abundance. Rathmelton is a beautiful village on the banks of Lough Swilly: see Sir J. Stewart's handsome seat. The scenery around is delightful; much planting, a fine river, and every appearance of increasing industry and comfort. W. of Rathmelton is the bridge of Loughaugh, an arch of 52 feet span. Ascend Mount Alt, on the summit of which a lake with most extensive prospect, combining ocean and mountain scenery. LIFFORD, 28 m. N.E. of Donnegal, is prettily seated on the river Foyle, and is the assize town for the county. The tourist will here find the inhabitants a complete Scotch colony. RAPHO, 24 m. N.E. of Donnegal, was an episcopal city, but now a dilapidated village.--See the Episcopal Palace, once a Castle which stood a siege in the Civil Wars: also the modernized Cathedral. Near Ballybofy see Lough Mourne, and the dreary mountains of Barnsmore. TORY ISLAND, which lies about 3 leagues from the main, N.W. from Sheephaven, contains the ruins of a monastery and of seven churches, having formerly been a "station," or place of Catholic penance. MINERALS. Sandstone and basaltes or whinstone, with pieces of coal imbedded, are frequent in Kilbarrow and Kildoney. Emery is also found in the same vicinity, and the chalybeates announce the existence of iron. Lead and iron ore are to be found in the mountains. BOTANY. _Galium boreale_, Crosswort Madder:--in mountainous meadows. _Gnaphalium sylvaticum_, Upright Cudweed:--in sandy pastures and woods. [Illustration: _T. Fielding fc._ _View from Warren Point Near Newry._] DOWN.