Leaving Carlow Town, the Barrow Way crosses to the right bank of the river as it heads south from the Graiguecullen Bridge. On the east bank of the river here is Carlow Castle, which was built by the Norman settler William Marshall. However, the castle was accidentally destroyed during the 19th century when an attempt to refurbish it, using explosives, failed spectacularly.
The towpath leads you to Carlow Lock, then rejoins the river as you leave the town behind and emerge into rich farmland.
Then the towpath passes Clogrennan Weir and joins a long side channel, with hedgerows of bramble, blackthorn and elder.
The trail goes through the yard of a lock house, and up ahead you pass some of the ruins of the 15th century Clogrennan Castle. You can also see the 19th century Cloydagh Church up ahead.
Soon the towpath leaves the road. A lush and green side canal brings you to scenic Milford Lock and Bridge, where there river splits around small islands.
Across the river here is the imposing facade of Milford Mills, which was destroyed by a fire in 1862. Later, in the 1890s, a turbine here was used to generate electricity that brought street lighting to Carlow town. Hydroelectricity is still produced here today.
You emerge back to the river, where there are tall and thick woods on the far bank. The towpath goes under the M9 motorway and then splits around the Orchard Islands.
The towpath continues past hedgerows rich with willow and alder, and you arrive down a short side channel to the weir and lock at Rathvinden. Then you go under Cardinal Moran Bridge and the Barrow Way eventually reaches Leighlinbridge (pronounced Lock-len-bridge). Part of the bridge here is said to date from the 1320s, and this pretty village is well worth a short stroll around.