In South-East Spain the brothers Siret have found corridor-tombs in which the chamber is cut in the rock surface and roofed with slabs; the entrance passage becomes a slope or a staircase. Here we have a parallel to the Giants' Graves of Sardinia, which are built usually of stone blocks on the surface, but occasionally are cut in the solid rock. Other tombs in the same district show the common megalithic construction consisting of a base course of upright slabs surmounted by several courses of horizontal masonry (Fig. 14). The chamber is usually round, and may have two or more niches in its circumference. It is roofed by the successive overlapping or corbelling of the upper courses. The vault thus formed is further supported by a pillar of wood or stone set in the centre of the chamber. On the walls of some of the chambers there are traces of rough painting in red. The whole tomb is covered with a circular mound. In the best known example at Los Millares there are remains of a semicircular facade in front of the entrance, as in many other megalithic monuments. [Illustration: FIG. 14. Corridor-tomb at Los Millares, Spain. (After Siret.)] The finest, however, of all the Spanish monuments is the corridor-tomb of Antequera in Andalusia. It consists of a short passage leading into a long rectangular chamber roofed with four slabs. Within it on its axial line are three stone pillars placed directly under the three meeting-points of the four slabs, but quite unnecessary for their support. The whole tomb is covered with a low mound of earth. In the great upright slab which forms the inner end of the chamber is a circular hole rather above the centre. It is not the plan of this tomb, but the size, that compels the admiration of the beholder. He stands, as it were, within a vast cave lighted only from its narrow end, the roof far above his head. The rough surface of the blocks lends colour to the feeling that this is the work of Nature and not of man. Here, even if not in Stonehenge, he will pause to marvel at the patient energy of the men of old who put together such colossal masses of stone. Among the corridor-tombs of Spain must be mentioned a wedge-shaped type which bears a close resemblance to those of Munster in Ireland (cf. Fig. 7). In Alemtejo, south of Cape de Sines, are several of these, usually about 6 feet in length, with a slight portico at one end. A further point of similarity with the Irish monuments is seen in the corridor-tombs of Monte Abrahao in Portugal, where the chamber walls seem to have been reinforced by an outer lining of slabs. Remains of eighty human bodies were found in this tomb, together with objects of stone and bone, including a small conical button similar to that of Carrowmore in Ireland.