Overview
The Glashaboy has never been much of a wild river; it was put to work. Through the 1800s its water turned the woollen factories and mills that Glanmire grew up around, and the town still sits in the river’s lap, in a wooded valley about five miles east of Cork city. For a visitor it makes a low-key outing rather than a destination: a river, a few old stone bridges, and a new public greenway, with the river flowing on towards Cork Harbour.
The mills and the flood scheme
Glanmire grew up around the river. Through the nineteenth century the settlement expanded into a working village powered by the Glashaboy, with woollen factories and water mills lining the banks and employing local families. The bridges and a scatter of stone remains are what’s left of that industry; Glanmire Bridge itself is a recorded monument and a protected structure.
The river’s habit of swelling in heavy rain has always been the catch. The worst of it came in June 2012, when the Glashaboy burst through Glanmire and Sallybrook and forced people from their homes. The river and its tributaries are now the focus of a flood relief scheme in Glanmire and Sallybrook, with the Butlerstown and Glenmore streams among the tributaries involved. Check the scheme page for the current state of the works.
A public walk or cycle
Cork City Council opened the Glanmire Greenway in August 2026. One of its new bridges crosses the Glashaboy into John O’Callaghan Park. The other crosses the Butlerstown River, with the route continuing towards the existing shared path at Glanmire Bridge.
Follow the marked shared route and any temporary signs around works. Keep away from the river’s edge in high water, and keep to the public route rather than the banks. In Glanmire you can see the old bridges, the Old Glanmire Rectory and St Mary’s and All Saints’ Church.
Getting there
Glanmire is an easy run from Cork city, and buses from the city centre serve the town; check current Bus Éireann timetables before you rely on one. Check local signage for parking and permit zones before you leave a car.
Near the river’s mouth, where the Glashaboy’s water finally reaches the harbour, Blackrock Castle and its observatory make an obvious add-on if you’re heading back toward the city.