The prehistoric station of _La Muela de Chert_ in Maeztrago reminds us of those of Portugal. It is situated on a little eminence, protected on the north and east by the natural escarpment of the plateau, and on other sides by a wall of some height made of stones without mortar. Some foundations of an oval shape, on which doubtless were built the homes of the inhabitants, can be made out in the middle of the _enceinte_. We can, however, but repeat here what we have said so often elsewhere, that it is impossible to fix the exact date at which these intrenchments were made. The discovery, however, of polished flint hatchets, diorite lance-heads, and a few bones of ruminants and cerviæ unknown in Spain in prehistoric times, would appear to point to a very considerable antiquity. Lastly, two young Belgian engineers24 have lately made out between Almeria and Carthagena a considerable number of prehistoric stations in which can be traced successively the different Stone ages and those of Copper and of Bronze. Several of these stations (Fig. 85) are regular fortified camps, protected by thick stone walls cemented with a thin layer of clay. The fire which destroyed the habitations has left behind, beneath the ashes and cinders, numerous objects, with the aid of which we are able to form a picture of the life led by the men who built the fortifications, and we know that they were agriculturists, for the very stores of grain have been found charred and agglutinated by fire. In the more recent stations flint, which was in the earliest time the one material used, has disappeared and is replaced by the copper, of which a plentiful supply was found in the rich mines riddling the mountains. Excavations have even brought to light the workshop of the metallurgist, with its moulds and vases converted into crucibles, its essays at new forms, its scoriae, and lastly its finished weapons, showing real skill in their production. Although it is impossible to assign to them a definite date, we must, to make this part of our work complete, say a few words on the earthworks met with in Roumania. A former minister of that principality, M. Odobesco,25 classes them as _valla, tumuli_, and _cetati de pamentu_ or citadels.