Everyone now accepts that the World is not set in stone: chunks of the planet lumber about the surface of the globe grinding past each other or colliding directly and heaving up mountain ranges. 400 million years ago, during the Caledonian Orogeny [Scottish mountain-building in normal-speak] in the Devonian Period, the NW and SE sections of what is now Ireland came together with a rock-melting clunk. The fractal nature of geology suggests that if an island like Ireland was once in two parts, a smaller area can be joined up too. The Blob has discussed two examples [Middle Island and its penguins; and Peñón de Vélez de la Gomera in not-Morocco] of once-upon-an-islands that have become more or less joined to the mainland in my lifetime. It cuts both ways: the South and East coasts of Wexford in the extreme Sunny SE of Ireland are disappearing quite rapidly due to coastal erosion. Land-loss and erosion is a central metaphor in Colm Tóibín's brilliant novel about the history of our Republic The Heather Burning. The Scilly Isles were once a more substantive chunk of dry land and Scillonians can still walk or wade between some of the current islands at low Spring tides.