It has been already said that the range of the Tandil gradually declines to the eastward till broken by a wide vale, which commences about twelve miles from the new fortification; the vale in question extends for a distance of forty-two miles:--many streams run through it, some few of which, inclining towards the coast, fall into the sea, though the greater part of them are lost in swamps in the low lands which intervene. It is the greatest break in the chain, and, from its rich pastures, a favourite resort of the Indians. They call it the Vuulcan, which signifies, in their language, an opening; and thence the sierra, which bounds it to the eastward, also takes its name. In many maps it is written Volcan, which has led to the erroneous idea of there being a volcano in those parts. From the Vuulcan the range runs in a continuous line for thirty-six miles towards the sea, presenting, for the most part, towards the north the appearance of a steep dyke or wall. On the summits are extensive ranges of table-land, well watered, and with good pasturage, to which the Indians, who are well acquainted with the craggy ravines which alone lead to them, are in the habit of driving their horses and cattle, knowing that the nature of the ground requires but little care to prevent their straying. At a short distance from the coast the hills break off in stony ridges, running down to the sea, and forming the headland of Cape Corrientes, in latitude 38° 6´, and further south a line of rocky cliffs, which bounds the shore as far as Cape Andres. Upon the borders of a lake a short distance from Cape Corrientes were discovered the remains of the settlement formed by the Jesuits in the year 1747,--a site chosen with all their characteristic sagacity, well suited for an agricultural establishment, of easy access to the sea, and with great capability of being rendered defensible. It is a striking proof of the indomitable nature of the pampas tribes that all the efforts of the missionary fathers to reduce them to habits of order and industry only ended in disappointment, and, after years of fruitless endeavours, to their being obliged to fly from an establishment where their lives were no longer safe. The Indians of the pampas, like the Arabs of the desert, inseparable from their horses, and wild as the animals they ride, were not, like the more docile people of Paraguay, to be subjected to the strict rules and discipline which it was the object of the fathers to introduce amongst them. The vestiges of their buildings, and the fruit-trees planted by them, are the only evidences remaining of their pious but unavailing labours.