Exploring the popularity of the Pontcysyllte Aqueduct

The Pontcysyllte Aquaduct near Llangollen used to be one of the hidden gems of Wales... until it was given World Heritage Status five years ago.

Now its popularity is higher than ever, with people visiting from around the world as Ian Lang reports.

It's the longest and highest cast iron aqueduct in the world.

Built by Thomas Telford and William Jessop, it was completed in 1805.

It cost under £50,000, which in today's prices would work out at around £4m.