By Pyevtsov) as the Ambal-ashkan, Kalga-lagan and Ara-tagh.
By Belfast Lough and the Lagan river dividing it from the county Down, W.
The valleys of the Bann and Lagan, with the intervening shores of Lough Neagh, form the fertile lowlands.
==Geology== On entering the county at the south, a scarped barrier of hills is seen beyond the Lagan valley, marking the edge of the basaltic plateaus, and running almost continuously round the coast to Red Bay.
The Lagan Canal connects Lough Neagh with Belfast Lough.
To Dublin Bay; the Boyne, fed from the central plain and discharging into Drogheda Bay; from the mountains of county Down, the Lagan, to Belfast Lough, and the Bann, draining the great Lough Neagh to the northern sea; the Foyle, a collection of streams from the mountains of Tyrone and Donegal, flowing north to Lough Foyle.
In post-Glacial times, a subsidence admitted the sea into the Lagan valley and across the eastern shore in several places; but elevation, in the days of early human occupation, brought these last marine deposits to light, and raised the beaches and shore-terraces some 10 to 20 ft.
In Ulster the Bann navigation connects Coleraine, by means of Lough Neagh, with the Lagan navigation which serves Belfast; and the Ulster canal connects Lough Neagh with Lough Erne.
Acting on the queen's explicit instructions, Essex, after some ill-managed operations, had a meeting with Tyrone at a ford on the Lagan on th 7th of September 1599, when a truce was arranged; but Elizabeth was displeased by the favourable conditions allowed to the O'Neill and by Essex's treatment of him as an equal.
It is a seaport of the first rank, situated at the entrance of the river Lagan into Belfast Lough, 1121 m.
Four bridges cross the Lagan; the Queen's Bridge (1844, widened in 1886) is the finest, while the Albert Bridge (1889) replaces a former one which collapsed.
At Newtonbreda, overlooking the Lagan, was the palace of Con O'Neill, whose sept was exterminated by Deputy Mountjoy in the reign of Queen Elizabeth.