The river rises in the southern slopes of Croghan Mountain in north Wexford on the County Wicklow border.

Veering southwest it passes under the R725, then continuing southwestwards it flows beneath the N11 national primary route at the village of Camolin.

It is crossed by the Dublin - Wexford railway four times as it flows past the town of Ferns before joining the River Slaney north of Enniscorthy.

In Wicklow and North Wexford, herds of deer can be seen, as well as mute swans, dippers, mallards, grey herons and kingfishers.

At dusk, bats, owls and otters may be seen, while the mudflats of the Slaney estuary are favoured by black-headed gulls, redshanks and oystercatchers.