The mosaics of Ravenna are surely among the world's most beautiful artistic creations; I had never seen them before except in books and I was so grateful for the chance to travel to Ravenna by train while we were staying in Bologna. All of the ancient churches in Ravenna dazzled me, but I found I loved the Basilica di San Vitale the most because of the green mosaics of stone, tile and glass which are the organizing principles of this magnificent work of art. I kept trying to think what green it was and where I had seen it: was it like Chinese celadon? I realized the last place I had seen colors like this was in Yellowstone National Park in June, in the beautiful spring green of sedges and grasses at Rescue Creek. I think the artists of San Vitale were definitely saying something about the life-giving properties of faith; the figures stand on verdant, flower-strewn meadows, where streams flow and birds drink, ducks paddle. It is a transcendant Byzantine vision of peace and harmony.