Some sacred sites such as that at Pico Dobra, in Besaya Valley date to Pre-Roman times. On the other hand, there is an altar dedicated to the god Erudinus, dated to 399 CE, demonstrating that in Cantabria, these rites persisted after the adoption of Christianity as the official religion of the Roman Empire. Certain place names also indicate the presence of ancient sacred places. These include Peña Sagra ("Sacred Mount"), Peña Santa ("Saint Mount"), Mozagro ("Montem sacrum" or "Sacred Mount") and Montehano ("montem fanum" or "Mount of the Sanctuary"). The Convent of Saint Sebastian of Hano dates to the 14th century CE but a small chapel pre-existed the monastery on the same site.