[4] The comune borders the following municipalities: Agliano Terme, Canelli, Castiglione Tinella, Costigliole d'Asti, Moasca, and Santo Stefano Belbo.

The Rapulé Fair is the ideal opportunity to visit the Calosso Castle, kindly opened for the occasion by the owners, the Baroque Church and the restored wooden choir of the Parish of San Martino and the four ancient staircases of the historic center.

[5] Source:[6] The first document in which the town is mentioned is an act from 960 which cites a certain Arimanno de Calocio as a witness to an exchange of land by Brunengo, Bishop of Asti between 934 and 964.

At the beginning of the 12th century Calosso became part of the consortium of Acquosana together with the lords of Agliano, Vinchio, Canelli, San Marzano and Castelnuovo Calcea.

In 1531 Calosso, with the County of Asti, became part of the territories controlled by the Savoys and with the beginning of the VII century and the War of the Monferrato Succession, it was involved in an endless series of occupations by the various passing armies.

In fact, at the beginning of the 17th century, Calosso was besieged by the Spanish and later recovered by the Savoys, thanks also to Captain Catalano Alfieri who, at the head of the French troops, had the entire castle surrounded by enormous palisades.

Named after San Martino, bishop and confessor, it was built in the last decades of the 1600s, the church has a façade full of friezes in its central, high and slender part, composed of two superimposed bodies divided with pilasters and ending with a tympanum.

It was clear that the eighteenth-century frescoes attributed to De Canis and to the youthful period of Giovanni Carlo Alberti from Canelli, who lived between 1670 and 1727, were then destroyed.