The canal boat drifted gently across the sky, 40 metres above the ground. Two men in a canoe followed. They were wearing lifejackets, although parachutes might have been more appropriate.
There is, it is safe to say, nowhere else in the world that you can float your boat so far off the ground as on this bit of the Llangollen canal, on Thomas Telford’s masterpiece, the Pontcysyllte aqueduct. It is a 307-metre long cast-iron trough perched on 18 stone arches that stride across the Dee valley in north Wales, a world heritage site that justifies its listing by being a genuine marvel of the Industrial Revolution.
