10th Lock, Ashtown

Lock 10 at Ashtown, near the Navan Road, matters to every skipper planning a through trip. Waterways Ireland warns that the shape of the chamber limits boats to less than 3.5 m beam, so a wide-beam barge that fits the 3.9 m locks elsewhere cannot pass between Dublin and the rest of the canal. Like the rest of the city flight it is worked only by arrangement with the Eastern Regional Office. For walkers, Ashtown is the start of the Royal Canal Way, the waymarked towpath trail that runs 144 km to Cloondara, usually walked in about six days. In the Phoenix Park, the visitor centre at Ashtown Castle, a tower house found hidden inside a demolished Georgian mansion, tells the park's history beside a restored Victorian walled garden.