2º. On the right of the above line the Tapada, or royal park of Mafra, offered some open ground for an attack. Yet it was strong, and, together with the pass of Mafra, was defended by a system of fourteen redoubts, constructed with great labour and care, well considered with respect to the natural disposition of the ground, and, in some degree, connected with the secondary post spoken of above: in front, the Sierra de Chypre, covered with redoubts, obstructed all approaches to Mafra itself. 3º. From the Tapada to the pass of Bucellas, a space of ten or twelve miles, which formed the middle of the second line, the country is choked by the Monte Chique, the Cabeça, or head of which is in the centre of, and overtopping all the other, mountain masses. A road, conducted along a chain of hills, high and salient, but less bold than any other parts of the line, connected Mafra with the Cabeça, and was secured by a number of forts. The country in front was extremely difficult, and a second and stronger range of heights, parallel to and behind the first, offered a good fighting position, which could only be approached with artillery by the connecting road in front, and to reach that, either the Sierra de Chypre, on the left, or the pass of the Cabeça de Monte Chique, on the right, must have been carried. Now the works covering the latter consisted of a cluster of redoubts constructed on the inferior rocky heads in advance of the Cabeça, and completely commanding all the approaches, and both from their artificial and natural strength, nearly impregnable to open force. The Cabeça and its immediate flanks were considered secure in their natural precipitous strength; and, in like manner, the ridges connecting the Cabeça with the pass of Bucellas, being impregnable, were left untouched, save the blocking of one bad mule road that led over them. 4º. From Bucellas (the pass of which was difficult and strongly defended by redoubts on each side) a ridge, or rather a collection of impassable rocks, called the Sierra de Serves, stretches to the right for two miles without a break, and then dies away by gradual slopes in the low ground about the Tagus. These declivities and the flat banks of the river offered an opening two miles and a half wide, which was laboriously and carefully strengthened by redoubts, water-cuts, and retrenchments, and connected by a system of forts with the heights of Alhandra, but it was the weakest part of the whole line in itself, and the most dangerous from its proximity to the valleys of Calandrix and Aruda.