Étel is situated on the west of the Megalithic district of which Carnae is the centre. It stands about 2 kilometres from the sea on the Rivière d'Étel. This so-called river is really an arm of the sea, which drains the extensive estuarine basin to the north-east, which is, in its way, almost another Morbihan (Little Sea) similar to the well-known one farther east. The tide rushes into the latter at a rate of from 7 to 11 knots per hour, at neap and spring tides respectively, and its ingress into and egress from the Rivière d'Étel cannot be much less. M. P. Le Strat, who has been much at sea in different parts of the world, considered that the incoming tide was rushing in at a rate of 7 or 8 knots an hour under the bridge of Lorrois, where the river narrows, when we passed it on October 11, 1909. The channel of the Rivière d'Étel is thus kept permanently open, and ships of from 50 to 150 tons are engaged in the tunny fishery and smaller boats in the sardine trade. Messrs. Peneau have a sardine-curing establishment at La Magoire, just opposite, across the river (Diagram, Text-fig. 1, p. 7).