The level of most of the area so designated ranges from 1,500 to 3,500 feet, but the plateau type is best developed in the Barquisimeto region, the dry, barren plains of which, with their cactus vegetation, suggest by their general features the dry bed of an ancient lake, in whose waters the small scattered hills formed islands, while the Andine spurs to the south and the Sierra de Aroa and similar mountain masses north of Barquisimeto, constituted its limits. Beyond the latter, and north of the Tocuyo River, while the larger part of the area maintains its more or less uniform elevation, three well-defined ranges rise from the plateau, in the Cordilleras of Baragua, Agua Negra, and San Luis; the last named is the largest, and extends for 110 miles parallel to the Coro coast, overlooking the Gulf of Venezuela. Practically the whole of this region is drained by the Tocuyo and its tributaries, the other rivers rising merely on its outer edges and falling direct to the sea; from this generalisation should be excepted a small area round Barquisimeto, in the catchment area of the river of the same name, which contributes its waters to the volume of the Portuguesa, and so enters the Orinoco. The Tocuyo, whose principal affluents are the Carora and the Baragua on its left bank, rises in the Andes and flows for some 330 miles in a northerly direction, changing to easterly in the lower river, before it empties itself into the Caribbean. While the southern part of this area is barren, all the lower slopes of the northern hills are forest clad and fertile, with _llanos_ in the Carora Valley and grass-covered summits above. To the south we have the Venezuelan Andes, stretching for some 300 miles south-westward to the Colombian frontier, and forming the highest land in the whole country.