Phlegmatic

I can get blase about UNESCO World Heritage Sites here in Cornwall where I live in one, but now my home town has one too!

Thomas Telford's Pontcysyllte aqueduct that carries the Llangollen Canal across the Dee Valley becomes Britain's 28th World Heritage Site.

http://news.bbc.co.uk/1/hi/wales/north_east/8122916.stm

It's not a bridge to go over if you suffer from vertigo. There is a railing between the single footpath and the 126ft drop, but not between the canal and the drop on the other side, so if you go over on a boat, you are very close to the edge.