Chirk Aqueduct

You may have heard of Pontcysyllte Aqueduct, which is famous for having a footpath on one side of the canal and a breathtaking drop to Mother Earth on the other. It turns out that it has a close relative a few miles away in Chirk on the Welsh-English border. You can walk on the tow path along one side and admire the views up and down the valley. On the other side is a narrow flat ledge and then an abrupt fall of 70 metres or so to the valley floor. At the other end of the aqueduct there is a signpost with an advertisement for The Samaritans, which felt a bit on the nose to me.
The second arched structure is a railway viaduct built some time after the aqueduct, and supposedly designed to be higher to establish the superiority of rail over water.