The protohistoric settlement was located at 850 metres above sea level, on a naturally defended plane and in an excellent position for controlling the surrounding territory. For this reason, this site must have had a very important function in the second Iron age, since at that time the economy was mainly based on the exchange of pastoral and mining/metallurgical resources between the Prealps and the plain. The scholar Gianbattista Pellegrini believes that the toponym “Bostel” refers to the control function, since it would mean “the place where there used to be a castle, ruins of a castle".
Ruling out the sporadic use of this area between the XII and the X century B.C., of which there is no visible remain, the settlement was built around the end of the V century B.C. and lasted until the II century B.C., when it was destroyed by a fire.
It is estimated that the settlement was constituted by about 600 partially underground houses distributed on at least three main terraces with streets and internal divisions which indicate a complex village plan. The house were of alpine type: an excavation in the ground constituted the bottom part of the building and was further lined with dry stone walls. The upper part of the building was probably of the load-bearing type, with an external wooden structure filled in with soil and pebbles. Little is known about the upper part but the recovery, on the floor of the house, of some stone slabs suggests that they might have been the bases for the vertical poles that supported a sloping rooftop. The inside of the house was accessible through a partially underground corridor and consisted in a squared room, with clay or planks floor. Its functions were those of warehouse, cooking place and stable for the cattle.
Of this settlement today it is possible to see the remains of some houses and the experimental reconstruction of one of them, which is also the core of the archaeological itinerary at the Bostel. The experimental reconstruction is a house whose walls are made of tree trunks, whose ceiling is covered with straw and whose inside is divided in functional areas according to the daily needs of the time. At the entrance door, the lock is a copy of an original one from the Iron age, which was found during the archaeological excavations.