The Rieti Valley or Rieti Plain (Italian: Piana Reatina or Conca Reatina) is a small plain in central Italy, where lies the city of Rieti, Lazio. It is also known as Sacred Valley and Holy Valley (Italian: Valle Santa) since saint Francis of Assisi lived here for many years and erected four shrines, which have become the destination of pilgrims.
It is the center of the Sabine region and an important part of the province of Rieti. Originated from the draining of the ancient Lake Velino, it is crossed by the Velino river and bordered by Monti Reatini and Monti Sabini.