The Way of St Francis takes the path of the saint in the Santa valley near Rieti. The plain is very fertile, and the mountains are covered by woods, dominated by oak, beech, chestnut trees, and hornbeams. The valley is crossed by the Velino, a deep blue river, which enters the city of Rieti bringing trout and Mallard ducks. Abundant fresh water of the Holy Valley is famous worldwide for its purity. The Sacred Valley itself was originally occupied by a huge lake, the Velino lake that was reclaimed in 271 BC by the Romans.