With thousands of islands adrift in cerulean waters and a long, labyrinthine coastline, Greeks have always traveled liquid highways. They built the world s first documented lighthouse at the Mediterranean port of Alexandria more than two-thousand years ago, and since that time countless sentinels have risen and fallen on Greek shores. Weather, warfare, erosion, and earthquakes have reduced some to rubble, but more than 100 traditional stone lighthouses still stand in Greece today old sentries keeping watch over every vessel, large or small, from freighters and tankers and cruise ships to...