To come to Greece and not go to Santorini would be to commit a sin. On approaching its coast, the capital, Fira, cuts an imposing figure from the top of its cliffs. The town is a true maze from one end to the other and is chock-a-block with white-washed houses, blue-domed Orthodox churches and flights of stairs leading onto even more narrow streets. Then, below, right down below, the deep blue sea with pleasure boats moored at the port.