The Swilly is named after a monster. An tSúileach means something close to ‘the many-eyed one’, from a legend that a man-eating water beast with countless eyes haunted the river until Saint Colmcille killed it. The story still does the rounds locally, enough that a Letterkenny DJ, Diarmuid O’Doherty, cut a track called A Monster in the River Swilly. The river itself rises on Glendore Mountain in west Donegal, about 15 m up, and runs roughly 42 km (26 miles) east through Letterkenny before it empties into Lough Swilly.
Be clear about what you’re coming to see. Through Letterkenny the Swilly is a working town river, not a beauty spot; the interest is in the history stacked along its banks, not the water itself. If you’ve half an hour, walk the town-centre stretch from Oldtown Bridge to the Devlin Way footbridge. The crossings between them carry most of the town’s story.
The bridges
Four bridges span the Swilly in Letterkenny, each from a different chapter of the town:
- Oldtown Bridge – the old stone crossing that was the town’s original link over the river.
- Port Bridge – a later road bridge near the site of the former commercial port.
- Rail Bridge – a relic of the closed railway that once tied Donegal into the national network.
- Devlin Way – the first pedestrian-only bridge over the Swilly, opened in November 2006. Designed by TS McLaughlin Structural Engineers and built by Bonnar Engineering, the €100,000 crossing has a maroon cambered steel deck, cast-iron lamps and a commemorative stone seat. It is named for the Devlin family, who gave part of their land to make it possible.
A working river
A canal was once meant to run from here. In the mid-1700s a scheme was floated to link the Swilly with the River Foyle by canal; it never got built. What did happen was smaller. From the 17th century the river was a crossing point for the growing settlement, and by the 1800s and early 1900s a modest shipping trade worked its narrow, bending channel, carrying coal and farm produce. The port closed in the 1960s when the channel proved too awkward to navigate, and the warehouses came down in 2001. The old coal yard still stands opposite the Mount Errigal Hotel. Upstream, the current is still put to work at Newmills Corn and Flax Mills, where the restored machinery runs off the river.
Fishing
The Swilly has long been one of the north-west’s better salmon and sea-trout rivers. Historically it gave up 300 to 400 salmon a year, the heaviest recorded at 11 kg (24 lb), with sea trout to 5.5 kg (12 lb); brown trout hold in the cleaner, slower stretches near the Forglug and Correnagh burns. Inland Fisheries Ireland manages the river, so check current permits, seasons and access with the IFI before you fish. The rules change from year to year and are enforced.
Downstream to Killydonnell
Where the river opens out toward Lough Swilly, the roofless ruins of Killydonnell Franciscan Friary stand on the shore, a quiet stop worth the short detour if you’re following the water north.
Getting there
The banks are reachable from several points in the town centre, with short paths down to the water near the main bridges, and they stay open year-round. The riverside strip supports grey herons, kingfishers and swallows, with the odd otter in the lower reaches and dragonflies through the summer.
If you make one stop, make it Newmills Corn and Flax Mills on the town’s eastern edge, where the Swilly’s flow still turns the wheel. It runs seasonally, so check the opening times before you go.