A recent trip took me to the Caldera de Taburiente on the island of La Palma on the western edge of the Canary Islands. The Canaries – not named for the birds but for dogs the pre-Spanish people kept and ate – are hugely popular destinations for sunseekers from northern Europe. The interesting geology of the islands is not what brings in the plane loads of tourists, though what they seek for a large part, results from geological processes.  Beaches, sun and alcohol, not necessarily in that order. Fuerteventura, Tenerife, Gran Canaria and Lanzarote all promise kilometers of beaches for the sun-deprived northerners to escape the long winters with.