A mountain village placed, mostly, in the valley basin formed by a branch of the Ledra river, closed to the north by the massif of Mount Cuarnan (1372 m) and to the south by Faeit and Cjampeón mountains. The territory of the municipality lies between 240 and 1,372 meters above sea level. The area is divided into three suburbs including numerous villages. The town hall is in Borgo Isola in the suburb of St. Helena. The town is surrounded by the almost uncontaminated nature and it is not hard to find wild animals in the area such as roe deer, foxes and sometimes even bears.

The meaning of the name, documented in the past as Montenario form, is not certain: beside the derivation from Montanarius, mountain dweller, commonly proposed, seems rather go valued the final “-Ars”, present in other place names (Gon-ars, Beiv-ars, Rutt-ars) and would seem to be indicative of a Lombard census, maybe mountainous, in opposition of the one placed in the valley by Artegna.

The district was heavily struck by the earthquake of 1976 whose epicenter was close to this area and that caused considerable damage to assets. Today most of the structures have been rebuilt and recovered.