Llangollen Canal, Denbighshire

Best for: Engineering marvels The Llangollen Canal has everything you could possibly associate with a canal along one towpath. On foot you’ll avoid the boat-jams that frustrate the high-season narrowboat skippers but you’ll still garner some of the most exciting canal experiences in a few hours’ walk. Start at the Horseshoe Falls, which supply the canal’s waters, and walk six miles along the narrow towpath under trees and cliffs to the Pontcysyllte Aqueduct (right). Completed in 1805, the masterpiece of Thomas Telford and William Jessop carries the canal and its towpath 126 feet above the valley of the River Dee. It’s a stunning walk (and an eerie experience for boat-drivers; they can’t see the aqueduct structure at all as they cross it). A few miles further on there’s 1380 feet of atmospheric gloom through the Chirk Tunnel, one of the few canal tunnels in Britain to have a towpath. Then for a break from canal walking, return on the marked trail over high ground between Trevor (by the aqueduct) and Llangollen.