It is a small island in the middle of a marshy basin called Green Lough, in the townland of Inishrush, barony of Loughinsholin, county Derry. Some years ago this marsh was a sheet of water about half a mile in circumference, the drainage of which was effected by means of a deep cut that carried its contents into the Clady river. About the centre of the lakelet was a circular artificial mound composed of clay and gravel, the sides gradually shelving downwards. It was girt with a circle--about one hundred and fifty feet in circumference--of oak piles, most of them still in position. Horizontal beams of oak were mortised in the upper ends, and upon this framework rested seemingly the foundation of a wooden house securely attached to the supporting timbers. An artificial causeway, leading from the western margin of the lough, appears to have formerly connected the crannog with terra firma. The sole discovery made was a fragment of chain-armour. The lake basin became again partly submerged owing to neglect of the drainage, and when Dr. Reeves visited the locality in 1859, he failed to reach the crannog. It remained, however, above water, prominently covered with a luxuriant growth of grass.[172] In 1560 O’Rourke was drowned “whilst going to sleep on a low sequestered crannog in _Muinter Eolius_,” county Leitrim. Under heading of the year 1544, crannogs in the county Antrim are referred to in the _Annals of the Four Masters_:--“O’Donnell marched with a force into the Routes, and took (i.) _Inis-an-Lochain_, on which was a wooden castle and an impregnable fortress in the possession of Mac Quillan; and after O’Donnell had taken the castle he gave the castle to O’Kane. On the same expedition O’Donnell took the castle of (ii.) _Baile-an-locha_, and he found much property, consisting of arms, armour, brass, iron, butter and provisions, in those castles. O’Donnell also took after that (iii.) _Inis-locha-Burrann_, and (iv.) _Inis-locha-Leithinnsi_, in which he likewise found much property.” (i.) _Inis-an-Lochain_ (_i. e._ the island of the little lake) lies in the river Bann, about a mile and a-half to the south of Coleraine. It is now called Loughan Island. The crannog had been erected, or perhaps, _re_-erected in 1170. (ii.) _Baile-an-locha_ (_i. e._ the village of the lake), anglicised Ballylough, and (iv.) _Locha-Leithinnsi_ (_i. e._ the lake of the half island), now known as Lough Lynch, are both situated in the parish of Billy. Lough Lynch originally covered about twenty acres, but has been drained, and the former island is now accessible by dry land. This crannog “is shown as the birthplace of Colkitto, a chief who figured in Montrose’s wars,” and who has found a place in Sir Walter Scott’s “Legend of Montrose,” as well as in one of Milton’s sonnets, written on the critics who cut up the title of his book “Tetrachordon:”--