In my blog about the Beara Peninsula, I mentioned that what is referred to as the Kenmare River, the body of water between the Beara Peninsula and the Iveragh Peninsula, looks more like a bay–not only because of its width, but because there is no sense of it running into the sea as you would expect of a river. It looks more like, well, the sea itself.

I just learned that the Kenmare River is what is called a “drowned river.” During the last Ice Age, glaciers cut gorges between the harder rock of what are now the mountainous peninsulas. When the glaciers melted, water began to run off the land through these gorges into the sea, becoming rivers. But eventually the rivers deepened the gorges to the point where the level of the river was lower than sea level. Sea water began to backfill the gorges, “drowning” the rivers. What amazing geography!