The prints show actual, early journeys rather than fantasy voyages. Some works are by artists who traveled and made drawings on which they later based their prints. During the Middle Ages and Renaissance, great distances were crossed by foot, horse, horse-drawn vehicle, or ship. Each mode of transportation involved extreme hazards, long delays, and major discomfort, and none guaranteed a safe arrival or return. Most travelers undertook the risk for commercial or religious purposes, but occasionally for sightseeing. Rome and Jerusalem were two of the most important pilgrimage destinations; Rome was also famed for its ancient monuments. Constantinople, capital of the Ottoman Empire, was not only a frequent stopping point along the way to Jerusalem, but also one of the world's richest centers of trade.