Monte de Estépar III, Burgos (2016). This grave on Mount Estépar measuring 4.70 x 1.90m contained 26 bodies in three layers, murdered between August and October 1936.Tresviso I (La Mesa), Cantabria (2016). After the fall of the northern front on 21 October 1937, many fighters fled to the Asturias mountains, forming guerrilla groups in the most rugged areas such as the Liébana Valley.