The River Liffey starts with lots of small streams in the Liffey Head Bog between Kippure and Tonduff in the Wicklow mountains. It flows for around 125 km (78 mi) through counties Wicklow, Kildare and Dublin. It flows into the Irish Sea at the mid-point of Dublin Bay. Most of its length is in Co.Kildare.
The Liffey has many tributaries. Its major tributaries include the King’s River, River Dodder, the River Poddle and the River Camac.
The Liffey has no natural lakes, and has only a few islands. There are a few areas with rapids, mostly as the river comes close to Dublin city.
There are dams built for three hydroelectric power stations along the river, at Poulaphouca, Golden Falls and Leixlip. A large reservoir is built at Poulaphouca.
Towns along the river include Ballymore Eustace, Athgarvan, Kilcullen, Newbridge, Caragh, Clane, Celbridge, Leixlip and Lucan before the river reaches the city of Dublin as it approaches its mouth.