The central mountainous region of the island is located in the province of Santa Clara, where a belt of mountains and hills following approximately northeast and southwest lines, passes through the cities of Sancti Spiritus and Santa Clara. Four groups are found here, one of which lies southwest of Sancti Spiritus and east of the Rio Agabama. A second group is included between the valleys of the Agabama and the Rio Arimao.
The highest peak of Santa Clara is known as Potrerillo, located seven miles north of Trinidad, with an altitude of 2,900 feet. A third group lies southeast of the city of Santa Clara, and includes the Sierra del Escambray and the Alta de Agabama. The rounded hills of this region have an altitude of about 1,000 feet although a few of the summits are somewhat higher.
The fourth group consists of a line of hills, beginning 25 miles east of Sagua la Grande, and extending into the province of Camaguey. The trend of this range is transverse with the general geological structure of the region.
East of the city of Santa Clara the hills of this last group merge with those of the central portion of the province. The summits in the northern line reach an altitude of only a thousand feet. The principal members are known as the Sierra Morena, west of Sagua la Grande, Lomas de Santa Fe, near Camaguini, the Sierra de Bamburanao, near Yaguajay, and the Lomas of the Savanas, south of the last mentioned town.
In the province of Pinar del Rio, we find another system, or chain of mountains, dominated by the Sierra de los Organos or Organ mountains. These begin a little west of Guardiana Bay, with a chain of "magotes" known as the "Pena Blanca," composed of tertiary limestone. These are the result of a seismic upheaval running from north to south, almost at right angles with the main axis of the chains that form the mountainous vertebrae of the island.
Between the city of Pinar del Rio and the north coast of La Esperanza, the Organos are broken up into four or five parallel ridges, two of which are composed of limestone, while the others are of slate, sandstones and schists. The term "magote," in Cuba, is applied to one of the most interesting and strikingly beautiful mountain formations in the world. They are evidently remnants of high ranges running usually from east to west, and have resulted from the upheaval of tertiary strata that dates back probably to the Jurassic period.
The soft white material of this limestone, through countless eons of time, has been hammered by tropical rains that gradually washed away the surface and carved their once ragged peaks into peculiar, round, dome-shaped elevations that often rise perpendicularly to a height of 1,000 feet or more above the level grass plains that form their base. Meanwhile the continual seepage of water formed great caverns within, that sooner or later caved in and fell, hastening thus the gradual leveling to which all mountains are doomed as long as the world is supplied with air and water. The softening and continual crumbling away of the rock have formed a rich soil on which grows a wonderful wealth of tropical vegetation, unlike anything known to other sections of Cuba, or perhaps to the world.
The valley of the Vinales, lying between the city of Pinar del Rio and the north coast, might well be called the garden of the "magotes," since not only is it surrounded by their precipitous walls, but several of them, detached from the main chain, rise abruptly from the floor of the valley, converting it into one of the most strangely beautiful spots in the world.
John D. Henderson, the naturalist, in speaking of this region, says: "The valley of the Vinales must not be compared with the Yosemite or Grand Cañon, or some famed Alpine passage, for it cannot display the astounding contrast of these, or of many well-known valleys among the higher mountains of the world. We were all of us traveled men who viewed this panorama, but all agreed that never before had we gazed on so charming a sight. There are recesses among the Rocky Mountains of Canada into which one gazes with awe and bated breath, where the very silence oppresses, and the beholder instinctively reaches out for support to guard against slipping into the awful chasm below. But the Valley of Vinales, on the contrary, seems to soothe and lull the senses. Like great birds suspended in the sky, we long to soar above it, and then alighting within some palm grove, far below, to rejoice in its atmosphere of perfect peace."
A mountain maze of high, round-topped lomas, dominates almost the entire northern half of Pinar del Rio. It is the picturesque remnant of an elevated plain that at some time in the geological life of the island was raised above the surface 1,500, perhaps 2,000, feet. This, through the erosion of thousands of centuries, has been carved into great land surges, without any particular alignment or system.
Straight up through the center of this mountainous area are projected a series of more or less parallel limestone ridges. These, as a rule, have an east and west axis, and attain a greater elevation than the lomas. They are known as the Sierras de los Organos, although having many local names at different points. Water and atmospheric agencies have carved them into most fantastic shapes, so that they do, in places, present an organ pipe appearance. They are almost always steep, often with vertical walls or "paradones" that rise 1,000 feet from the floor or base on which they rest.
The northernmost range, running parallel to the Gulf Coast, is known as the "Costanero." The highest peak of Pinar del Rio is called Guajaibon, which rises to an altitude of 3,000 feet, with its base but very little above the level of the sea. It is probably of Jurassic limestone and forms the eastern outpost of the Costaneros.
The southern range of the Organos begins with an interesting peak known as the Pan de Azucar, located only a few miles east of the Pena Blanca. From this western sentinel with many breaks extends the great southern chain of the Organos with its various groups of "magotes," reaching eastward throughout the entire province. At its extreme eastern terminus we find a lower and detached ridge known as the Pan de Guanajay, which passes for a few miles beyond the boundary line, and into the province of Havana.
Surrounding the Organos from La Esperanza west, and bordering it also on the south for a short distance east of the city of Pinar del Rio, are ranges of round topped lomas, composed largely of sandstone, slate and shale. The surface of these is covered with the small pines, scrubby palms and undergrowth found only on poor soil.
From the Mulato River east, along the north coast, the character of the lomas changes abruptly. Here we have deep rich soil covered with splendid forests of hard woods, that reach up into the Organos some ten miles back from the coast. Along the southern edge of the Organos, from Herredura east, lies a charming narrow belt of rolling country covered with a rich sandy loam that extends almost to the city of Artemisa.
Extensions, or occasional outcroppings, of the Pinar del Rio mountain system, appear in the Province of Havana, and continue on into Matanzas, where another short coastal range appears, just west of the valley of the Yumuri. This, as before stated, has its continuation in detached ranges that extend along the entire north coast, with but few interruptions, until merged into the mountain maze of eastern Oriente.
Outside of the mountainous district thus described, the general surface of Cuba is a gently undulating plain, with altitudes varying from only a few feet above the sea level to 500 or 600 feet, near El Cristo in Oriente. In Pinar del Rio it forms a piedmont plain that entirely surrounds the mountain range. On the south this plain has a maximum width of about 25 miles and ascends gradually from the shores of the Caribbean at the rate of seven or eight feet to the mile until it reaches the edge of the foothills along the line of the automobile drive connecting Havana with the capital of Pinar del Rio.
North of the mountain range, the lowland belt is very much narrower and in some places reaches a height of 200 feet as a rule deeply dissected, so that in places only the level of the hill tops mark the position of the original plain.
The two piedmont plains of Pinar del Rio unite at the eastern extremity of the Organos Mountains and extend over the greater part of the provinces of Havana and Matanzas and the western half of Santa Clara. The divide as a whole