The situation of the town is striking, the Newry Mountains and Slieve Gullion on the west, and the Mourne Mountains on the east, enclosing the narrow valley in which it lies.
The general surface of the county is gently undulating and pleasantly diversified; but in the northern extremity, on the borders of Lough Neagh, there is a considerable tract of low, marshy land, and the southern border of the county is occupied by a barren range of hills, the highest of which, Slieve Gullion, attains an elevation of 1893 ft.
Part of Lough Neagh is in the county, and there are many small loughs, such as Gullion, Cam and Ross.
It is penetrated by far younger intrusive masses at Slieve Gullion and Forkill.
The summit of Slieve Gullion is crowned by a large cairn, which forms the roof of a singular cavern of artificial construction, probably an early burial-place.