From Atlas and Cyclopedia of Ireland (1900)
SIZE AND POPULATION—Length from Athlone to the boundary point southeast of Clon-mellon, 43 ½ miles; breadth from Finnea to Kinnegad, 26 miles; breadth from the river Inny, near Ballynacarrigy, to the boundary near Rahugh, 21 miles; area, 708 ½ square miles; population 71,798.
SURFACE.—Westmeath contains no mountains. There are a number of low hills in the barony of Fore, from 500 to 849 feet high, and a few in the adjoining baronies of Corkaree and Farbill. The rest of the county—that is, nearly the whole area—is level, broken here and there by low swells and sandridges or eskers, but in general very flat, with a good deal of bog, especially in the south and east. But though level, Westmeath is generally very pretty, abounding in lovely quiet landscapes.
RIVERS.—The Inny, issuing from Lough Sheelin at the northern extremity of the county, forms the boundary between Westmeath and Cavan, during its short run of a mile by the village of Finnea, from Lough Sheelin to Lough Kinale. Issuing from Lough Kinale, it flows southward, forming the boundary between Westmeath and Longford for 6 miles, and then enters Westmeath beside Camagh Bridge; it continues its southern course to Lough Derravaragh, which it enters at its northwestern end; then flows out from the long western corner of the lake, and runs southwest into Lough Iron; issuing from which at the northwest corner, it runs westwardly, forms for 5 miles the boundary between Westmeath and Longford, and then enters Longford; having again run on the boundary of Westmeath and Longford for a mile, it finally enters Longford, and ends its course in the northeastern angle of Lough Ree.
The following are the Westmeath tributaries of the Inny. The Glore rises in Lough Glore, near Castlepollard, and flows northwest; the Gaine flows from Lough Drin and Brittas Lake, seat of Lough Owel, and enters the western arm of Lough Derravaragh; the Riffey comes from Longford, flows southeast, and joins the Inny halfway between Lough Derravaragh and Lough Iron; the Black River comes from Longford, flows parallel to the Riffey, and enters Lough Iron; the Rath River rises near the Hill of Ushnagh and flowing northwest, enters Longford; the Tang runs on the boundary of Westmeath and Longford for 3 miles, and then joins the Inny, just where the later touches Westmeath for the last time; the chief headwater of the Tang is the Dungolman River.
In the southwest of the county, the Breensford River runs westward from Twy Lough to Killinure Lough; and the Boor River runs west from near Moate, and joins the Shannon at the boundary of Westmeath and Kings County.
The Brosna rises near Mullingar, flows south-westward through the town, and enters Lough Ennell; issuing from which at the southern end, it flows southwestward through Kilbeggan, a little below which it forms the boundary between Westmeath and Kings County; then crosses a corner of Westmeath, and enters Kings County beside Lismoyny. The Monaghanstown River flows southeast and enters Lough Ennell near where the Brosna issues from it. West of this the Gageborough River draws its headwaters from Westmeath, and enters Kings County at Horseleap to join the Brosna.
All the rivers of the east and southeast flow to the Boyne. These are as follows: The Stonestown River draws some of its headwaters from Meath, near Clonmellon, flows across the northeast corner of Westmeath, and again enters Meath; the Dale flows southeastward, and forming for a short distance the boundary between Meath and Westmeath a little east of Killucan, finally enters Meath; the Kinnegad River flows by Kinnegad, running on the boundary between Meath and Westmeath, and then enters Meath; southwest of which, the Milltown River rises in the barony of Fartullagh, and leaves Westmeath to join the Yellow River before its confluence with the Boyne.
Thus the eastern edge of the county belongs to the basin of the Boyne, and all the rest to the basin of the Shannon.
LAKES.—Westmeath is remarkable for its fine lakes. Lough Ree lies on the western border, of which Lough Killinure and Coosan Lake, which lie wholly in Westmeath, are only branches.
Lough Shelien and Lough Kinale on the northern border belong chiefly to other counties, the first to Cavan, and the second to Longford. Near these on the east, in the barony of Kilkenny West, are the small lakes of Doonis, Creegan, Makeegan, Waterstown, Robin's Lake, and Twy Lough. Glen Lough, in the northwest, lies on the boundary with Longford. The three small lakes, Lough Naneagh, White Lough and Lough Bane, in the northeast, are on the boundary with Meath.
Lough Ennell or Belvidere Lake, southwest of Mullingar, is 5 miles long and 2 miles broad. Lough Owel, northwest of Mullingar is 4 miles long and 2 miles broad. Lake Derravaragh north of Lough Owel, is 9 miles long, and very narrow except at the northwest end, where it widens to 3 miles; at the southeast end, the pretty hill of Knockeyon rises directly over the lake to a height of 707 feet. Lough Iron, northwest of Lough Owel, is 2 ½ miles long and less than half a mile broad; a little north of which is the small Lough Garr. Two or three miles northeast of Mullingar is a group of small lakes, Lough. Drin, Brittas Lough, Slevins Lake and Lough Sheever.
ISLANDS.—The following Islands of Lough Bee belong to Westmeath; on most of them there are church ruins. Inchmore; Nuns Island; Inishturk; Leveret Island; Hare Island in the south, on which St. Kieran erected a church before he founded Clonmacnoise, and which now contains the ruin of a church dedicated to him; and Inchbofin, on which St. Rioc erected a church in the 6th century, and which still contains some ecclesiastical ruins. In Lough Ennel is Great Island, and near it Croincha or Cormorant Island, on which Malachy, king of Ireland, died in 1022. In Lough Owel is Church Island, on which is the ruin of a church.
TOWNS.—Mullingar (4,787), the assize town, stands on the Brosna near its source, in the center of the county, and nearly midway between Loughs Ennel and Owel. Lower down on the Brosna, in the extreme south of the county, is Kilbeggan (1,033). Athlone (6,755 of whom 3,683 are in that part of the town belonging to Roscommon), built on both sides of the Shannon a little below where it issues from Lough Bee, is the most considerable town between Dublin and Galway, and was always an important place on account of commanding a pass on the Shannon. In this southwestern division of the county, near the boundary with Kings County, is Moate or Moate-Granoge (1,462), beside which is the great Moat, an ancient fortified dun, which gave name to the town. In the north of the county, near Lough Lene, is Castlepollard (852); and beside the southeast boundary is Kinnegad (424). In the northeast is the village of Delvin (276), which retains the name of a very ancient territory; near which, beside the boundary with Meath, is Clonmellon (456).
ANCIENT DIVISIONS AND DESIGNATIONS.—The western half of the county constitute the ancient district of South Teffia, separated from North Teffia (see Longford) by the river Inny. The ancient district of Kineleagh, possessed by the family of MacGeoghegan, included a portion of the south of Westmeath, nearly coincident with the present barony of Moycashel. The barony of Kilkenny West is coextensive with the old district of Curcne. One of the ancient districts called Delvin, viz., Delvin-more or the Great Delvin, was in Westmeath, and is still represented by the present barony of Delvin in the east of the county. The baronies of Farbill, Corkaree Moygoish, and Brawney, also retain the names of old historic districts.
The Hill of Ushnagh, between the village of Ballymore and Lough Ennel, was constituted a royal residence by Tuathal the Acceptable, king of Ireland in the first century, who erected a palace on it. He also instituted a yearly meeting to be held on the hill on the first of May and the succeeding days, at which games were celebrated and various pagan rites were performed. Before this king's time the five provinces of Ireland met at the Hill of Ushnagh, and the point of meeting was marked by a stone called Aill-na-Mirenn, or the stone of the divisions; this stone still remains on the hill, and is now called Cat-Ushnagh.