The Vartry rises in
Calary Bog under the
Great Sugar Loaf mountain in northern
County Wicklow. Passing through a Dublin municipal reservoir complex, it flows east towards
Ashford under Annagolan Bridge, and down through
Devil's Glen. From there it passes the Nun's Cross Bridge (dating from the 18th century) on through Ashford, under the
N11 road and continues eastwards into Broad Lough, which flows towards Wicklow town. Broad Lough is a narrow lake which lies approximately 1 km north of Parnell Bridge in
Wicklow town (at its closest point) and approximately 4 km north of Parnell Bridge (at its furthest point). This lake and surrounding wetlands evolved when a
sand spit formed along the coastline cutting off the Vartry from its original egress. This sand spit is called The Murrough/Murragh and it carries the Dublin to Wicklow coastal railway line built in the 1860s. Broad Lough drains southwards into the
Irish Sea through Wicklow town centre and harbour. The name of this stretch of water (approximately 1.5 km in length) is disputed. It is variously called the River Leitrim, the Broad Lough Estuary ==Historical references==