Overview
Few short walks in the southeast pack in as much history per kilometre as the Grennan Loop. In 6.6 km out of Thomastown in County Kilkenny you pass two castles, a ruined medieval church with its east window still standing, an old mill and a hurler cast in bronze, along footpath, the banks of the River Nore, deciduous woodland and quiet country road. Red arrows on a white background waymark the route; it climbs a modest 60 metres and takes about two hours at a moderate pace. It’s free, and dogs are not allowed, because of livestock on the land.
If you only do part of it, walk the stretch to Grennan Castle and the Thomple: that’s the history in a nutshell, and the castle mound gives you the best of the valley views.
History
Grennan Castle sits on a low mound above the river and began around 1210 as a timber motte-and-bailey, thrown up by Thomas FitzAnthony, the Anglo-Norman who became Seneschal of Leinster as English control pushed into the region. Within a decade the timber was replaced by a stone keep, roughly 18 by 13 metres with walls up to three metres thick, its entrance raised on the east side for defence. The estate around it grew into a self-sufficient holding with a water-corn mill, forge, bakery and a wine cellar that shipped down the Nore.
Cromwell’s forces besieged it in 1650, and a survey in 1655 still described ‘a faire castle with many outhouses, stables’. By the early 1800s the keep had fallen into disrepair, at one point serving as a cattle shed before parts of the outer wall were lost. What stands today is a working lesson in how a Norman lordship held a river.
What to see and do
Historic and architectural stops
- Grennan Castle – The stone keep still dominates the valley, with traces of the original earthworks around it and long views across the river and farmland.
- Sweetman Castle – A 14th-century tower now half-taken by ivy, a later phase of the same medieval story.
- The Thomple (Church of Grennan) – The ruined church whose intact east window is the single most striking thing left standing on the route.
- Dysart Castle – Another castle ruin on the loop, near the Nore. (Not to be confused with Dysert O’Dea in County Clare.)
- Grennan Mill – A restored 13th-century mill on the river, now home to the Grennan Mill Craft School.
- Ollie Walsh statue – A bronze of the Kilkenny hurling goalkeeper, a local landmark on the walk.
Nature and interactive features
The trail follows the pebbly banks of the River Nore, where ducks, swans and sand martins can often be spotted. The surrounding deciduous woodlands host oak, birch, beech, spindle holly, wild garlic, wood anemone and bluebells. Buzzards frequently soar overhead, making it a rewarding route for casual birdwatchers.
Along the Grennan Woods section, Trail Kilkenny has installed audio points. Scanning the QR codes unlocks short narrations about the local trees, wildlife and folklore, adding an educational layer to the walk. Benches and a wooden swing at a designated viewpoint provide a natural resting spot to take in the scenery.
Practical Information
- Start point: Market Street, Thomastown town centre.
- Trail markings: Red arrows on a white background.
- Distance & time: 6.6 km loop; approximately 2 hours at a moderate pace.
- Elevation: 60 m total ascent.
- Parking: On-street parking in Thomastown is limited; a common workaround is the GAA car park on non-match days. There’s also a viewpoint with parking and picnic tables on the road towards Inistioge.
- Facilities: Public toilets are located in Thomastown town centre and at the nearby Inistioge visitor centre. Benches and a swing are placed along the route.
- Safety: The path is well-marked but includes modest climbs and river-edge sections. Sturdy walking shoes are recommended. The trail is not wheelchair-accessible due to uneven ground and stile crossings.
- Dog policy: Dogs are not permitted on the route.
Getting There
By car – From Kilkenny city, take the N77 south for approximately 15 km to Thomastown. Turn left onto Market Street; street parking is available near the town hall. By bus – Bus Éireann route 73 (Kilkenny–Waterford) stops in Thomastown, a short walk from Market Street. By train – Thomastown is on the Dublin–Waterford line; the station is about 1.3 km from the town centre and the start of the loop.
Nearby Attractions
- Inistioge – A riverside village known for craft shops, the historic Inistioge Bridge and the Irish Wool Centre.
- Goresbridge – Another scenic Nore-river settlement featuring a historic bridge, local cafés and additional walking paths.
- Thomastown–Inistioge route – For those seeking a longer day out, the Grennan Loop connects to this extended riverside walking trail.
Seasonal Highlights
- Spring – Woodland floors carpet with bluebells, and the air carries the distinct fragrance of wild garlic.
- Summer – Extended daylight makes the riverbank sections ideal for a relaxed pace and a packed lunch.
- Autumn – The Nore valley transforms with reds and golds, offering excellent conditions for landscape photography.
- Winter – The trail remains open year-round, but recent rain can leave sections slick and muddy. Waterproof footwear is essential.
Accessibility and family tips
The route suits families with children of about seven and up who can manage short stiles and uneven woodland paths; it’s not one for a buggy. Bring water and a snack, because there’s nothing to buy once you leave the town. Sport Ireland grades the loop Moderate, though it’s on the easier end of that, and the real variable is rain: the low sections near the Nore turn to mud fast, so after a wet spell wear boots and check the river isn’t up before you set off.