Its concentration of ancient and modern history, culture and traditions finds few parallels in Sardinia. Rising up the eastern slopes of Monte Arci, Ales is the main town of Marmilla and perhaps the smallest bishopric in Italy, as well as being the ‘historical record’ of the island thanks to its ancient Archive. Its territory is rich in archaeological treasures that, in prehistoric times, were linked to the presence of rich and precious deposits of obsidian in the mountain. Its Roman domination began with the founding of the colony of Uselis in 62 AD.
In the upper part of the village stands the majestic cathedral of San Pietro, built in 1686 under the dictates of the Genoese architect Domenico Spotorno. Within is a rare 14th-century crucifix. The same piazza in which stands the cathedral is overlooked by the Palazzo Vescovile (Bishop’s Palace), and the Oratorio della Madonna del Rosario. The urban structure and the monumental aspect of some buildings create an overall sense of the function as capital of the diocese, a position held since the Middle Ages.