The Blackwater Aqueduct carries the Royal Canal over the Enfield Blackwater at Kilmorebrannagh, about 3.5 km west of Enfield in County Meath. It is a stone canal-bridge: the towpath and the water you are walking beside cross the river on it, roughly 15 metres up. Set expectations honestly – this is a quiet waypoint on a long, flat towpath, not a headline attraction. You come for the walk or the cycle, and the aqueduct is a marker along the way rather than a reason to drive out on its own.
The canal beneath your feet is part of the line begun in 1789 and pushed through to the Shannon by 1817, built to move goods and people from Dublin to the west and to compete with the older Grand Canal. The aqueduct belongs to that westward extension. If it is canal engineering you are after, the larger Boyne Aqueduct further west, near Longwood, is the more impressive of the two crossings on this stretch.
Walking and cycling
The aqueduct sits on the Royal Canal Greenway, 130 km of level towpath running from Maynooth to Cloondara in County Longford, of which about 22 km lie in Meath. The surface is flat and made up, which is the whole appeal: pushchairs, casual walkers and cyclists of every ability manage it without trouble. There are no hills.
The numbers from Enfield give a sense of distances. Heading east toward Kilcock is roughly two and a half hours on foot or about 40 minutes by bike; west toward Longwood is about two hours walking or half an hour cycling. The standard way to do it is to cycle one direction between towns and take the train back, since Enfield, Longwood and the towns along the line are close to stations. Storyboards and map-boards at the Meath access points – Enfield, Longwood and Hill of Down – fill in the canal’s history as you go.
The Enfield Blackwater itself is a 24.5 km river that rises near Timahoe in north County Kildare and runs north to join the River Boyne at Donore. Brown trout are the main fish in it. The towpath here is quiet, used by walkers and cyclists rather than commuters.
Getting there, parking and dogs
Enfield is the natural base. It sits on the Dublin–Sligo railway line, so you can reach the greenway from Dublin in under an hour without a car, then walk or cycle the 3.5 km out to the aqueduct. The town keeps some of its Midland Great Western Railway heritage – the old station, warehouses and signal towers, still in use.
If you drive, park in Enfield and join the towpath there; there is no car park at the aqueduct itself, which is reached on foot or by bike along the canal. Dogs are welcome but must be kept on a short lead at all times. Take a flask – the path is open countryside, and the cafés and shops are back in Enfield village.
Nearby
Along the same route you will find the Enfield Fairy Trail (good if you have small children), Enfield Leisure Park, and the National Famine Way, the 165 km commemorative trail that follows the canal and the Royal Canal Greenway for much of its length.
The simplest plan: start in Enfield, cycle west to the aqueduct and on toward Longwood, and turn back when you have had enough – there is no ticket, no closing time, and the return is all downhill in spirit if not in gradient.