Riserva naturale dell'Abbadia di Fiastra, State nature reserve in Province of Macerata, Italy

The Riserva naturale dell'Abbadia di Fiastra is a protected area in the Province of Macerata featuring woodlands, cultivated fields, and streams across varying elevations. The site includes remains of a 12th-century Cistercian abbey and several small museums dedicated to local history and traditions.

The Cistercian abbey of Chiaravalle di Fiastra dates from the 12th century. Its monks kept a forest of about 100 hectares, later maintained by the Bandini family. The Fondazione Giustiniani-Bandini, recognised by presidential decree on 6 July 1974, joined the Marche region in a convention of 18 June 1984 creating the reserve; the Italian State recognised it on 10 December 1985.

The reserve's name comes from the Abbey of Chiaravalle di Fiastra, a 12th-century Cistercian monastery whose monks, and later the Bandini family, kept the roughly 100-hectare Selva standing. The protected area is split into three zones: an oriented nature reserve covering the Selva with a European Union Habitat Directive site, an anthropological reserve taking in the cultivated fields, the Palazzo Giustiniani-Bandini and the abbey, and a buffer protection area. The roe deer, reintroduced in 1957, appears on the reserve's emblem.

The reserve lies between 130 and 306 m across the municipalities of Tolentino and Urbisaglia, split into an oriented nature reserve (the Selva), an anthropological reserve with the abbey and Palazzo Giustiniani-Bandini, and a buffer zone. A straight gravel path bordered by grass and rows of trees crosses flat fields toward the woods. Waterbirds at the small lake Le Vene are watched from special hides.

A woodland called La Selva represents one of the last original hill forests of the region, protected for centuries first by monks and later by a private family. This intact forest offers a rare glimpse of the natural vegetation that once covered the entire Marche territory.