But the main factor which has assured success (and which in itself led up to the private efforts just named) took origin in the great Sierra de Grédos. This elevated region is the apex of the long cordillera of central Spain, the Carpeto-Vetonico range, which extends from Moncayo, east of Madrid, for some 300 miles through the Castiles and Estremadura, forming the watershed of Tagus and Douro. It separates the two Castiles, and passing the frontier of Portugal is there known as the Serra da Estrella, which, with the Cintra hills, extends to the Atlantic sea-board. Along all this extensive cordillera there is no more favoured resort of ibex than its highest peak, the Plaza de Almanzór, of 2661 metres altitude (= 8700 feet) above sea-level. In 1905, when the ibex were about at their last gasp, the proprietors of the _Nucléo central_, which we may translate as the _Heart_ of Grédos, of their own initiative, ceded to King Alfonso XIII. the sole rights-of-chase therein, and His Majesty commissioned the Marquis of Villaviciosa de Asturias to appoint an adequate force of guards. Six guards were selected from the self-same goat-herds who, up to that date, had themselves been engaged in hunting to extermination the last surviving ibex of the sierra, and whom we had ourselves employed during various expeditions therein. [Illustration: ON THE RISCO DEL FRAILE. SPANISH IBEX IN SIERRA DE GRÉDOS..] The ceded area comprised all the best game-country, defined as the "Circo de Grédos"--including the gorge of the Laguna Grande, the Risco del Fraile, Risco del Francés, and that of Ameál de Pablo, together with the wild valley of Las Cinco Lagunas--as shown on rough sketch-plan annexed. [Illustration: SKETCH-MAP OF THE _NUCLÉO CENTRAL_ OF GRÉDOS (A. _Alto del Casquerázo._ B. _Riscos del Fraile_, with the Hermanitos in front.)] In 1896 we estimated the stock of ibex at fifty head, and during the following years it fell far below that--by 1905 almost to zero. In 1907, after only two years of "sanctuary," it was computed by the guards that the total exceeded 300 head. In July 1910 we inquired if it were possible to estimate the present stock. In a letter (the composition of which would cost some anxiety) the Guarda of the Madrigal de la Vera--one portion only of the "sanctuary"--reports: "It is difficult to count the ibex. Sometimes we see more, sometimes less. Yesterday on the Cabeza Neváda we counted 39 rams and 22 females together. On the other side we counted 29 in one troop, 19 in another, 12 in another, besides smaller lots. We probably saw 160 or 170, and we could not see all. Some of the old rams are very big, and it would be advisable that some be shot." Another report (at same date) from the "Hoyos del Espino," estimates the ibex there to exceed 200 head. The two reports go to show that the continuity of the race is fairly secured.