Following the weakening of Siennese power at the end of the 16th century, the Val d’Orcia gradually declined in economic importance. The major hill towns of the area include Pienza (a separate World Heritage property), Montalcino, San Quirico d’Orcia, Castiglione d’Orcia, Rocca d’Orcia, Monticchello and Radicofani. The boundary of the World Heritage property coincides with the boundaries of the modern-day Park of Val d’Orcia (Parco Artistico Naturale e Culturale della Val d’Orcia). ‘The Val d’Orcia Artistic, Natural and Cultural Park’ (Parco Artistico Naturale e Culturale della Val d’Orcia) was created in 1999 to coordinate the management of the natural and cultural features of the region. Management responsibility in the Park of Val d’Orcia lies with the five municipalities (Montalcino, Pienza, San Quirico d'Orcia, Castiglione d'Orcia, Radicofani).