After arriving in Rome, we took our Orientation Walk and visited the Trevi Fountain. It is still customary to throw a coin in the fountain to make a wish. We detoured through an air-conditioned mall, a rare thing here, and continued to the Pantheon. The building and dome date back to ancient Rome. The original bronze doors still hang and are used daily. The ancient Roman architect created a dome of cement with walls of decreasing thickness to solve the problem of distributing the weight in order to close the opening. The dome itself is a perfect circle and is still the largest unreinforced concrete dome in the world. In Renaissance times, Brunelleschi studied this dome in order to create the dome of The Duomo in Florence. We also visited the Four Rivers Fountain by Bernini.