The article deals with the tumba (or tomba) and with the diffusion of this building type in the medieval rural territory of Rimini. By tumba we normally mean a fortified settling of modest dimensions, built on high ground in order to protect cultivated areas: its characteristics are well described into the De Agricoltura, a treatise written by Pietro de’ Crescenzi from Bologna at the beginning of XIV century. The historical origin of the type is strictly connected to the events of the so-called “new fortification”, in its turn dependent on both the agricultural vocation of the territory of Romagna, and its instability during the first decades of the XIV century. In the absence of aggregate residential complexes, the tumba was an important defensive point in the countryside. The article examines the architectonic characteristics of the type starting from the archeological evidence, concentrating finally on two pretty well preserved examples, the Tomba dei Battagli and the Tomba di Poggio Berni.