In a recent post on Easdale, I mentioned the Island of Seil. Since 1793, a single arch bridge has connected Seil to the mainland of Lorn south of Oban. The delicate sandstone arch on Tanera Beag brought the Clachan Bridge to mind. It spans the tidal Clachan Sound which is connected to the ocean, hence its common name "the bridge over the Atlantic". The narrow Clachan Sound runs straight for 1.5 kilometers before it joins the Seil Sound to the south to the Firth of Lorn to the north. Some think it must have been dug out as a canal but it is natural, occupying a fault line. It is a sheltered highlight on a circumnavigation of Seil but you need to get the tides right as the Sound can run like a river!
