The Sluice is located on the River Liffey near Lucan, west of Dublin, and is widely regarded as Ireland's best-known playspot for freestyle paddling. The feature is 4 to 5 meters wide and functions as a combination of a hole and a messy wave. While it is not particularly retentive, it is capable enough to allow modern freestyle tricks to be performed. The water is notably deep, so paddlers need not worry about bottoming out.

Water flow at the Sluice is controlled by the ESB (Electricity Supply Board), which releases water for electricity generation. The spot is considered worth paddling when the ESB is producing more than 1 megawatt of power. For current water level information, paddlers can contact the Canoe Centre in Dublin at +353 1 6264363 or check online resources. The site also features permanent slalom gates installed following in-river works completed in 2014, which were carried out in partnership with Canoeing Ireland.

To reach the Sluice from Dublin city, follow the signs for the M4/Galway/The West, passing Heuston Station. After approximately 2 miles beyond a major roundabout, take the exit just before the Lucan Spa Hotel, which sits on a hill ahead. Turn right at the T-junction, pass back under the N4, and look for a gravel track on the left. Parking is available there, and the Sluice is a 400-meter walk up the river track. The feature sits on the far river left side of a weir on the Liffey.

The Sluice also features as a notable point along the Liffey Descent race route, one of Ireland's major paddling events, where first aid and water-based rescue coverage is provided at the Sluice Weir location during the race.