The greater number of the Arawaks of Northern Brazil and Southern British Guiana are found within a broad savannah some twenty or thirty thousand square miles in extent, reaching from near the Venezuelan boundary to the western banks of the Essiquibo River and from the Amazon forests to the foot of the Pakaraima Mountains; or from 58½° to 63° W. Long, and from 1½° to 4½° N. Lat. It is a great undulating plain dotted here and there with grass-covered round-topped mountains. Besides these numerous single mountains there are also three short ranges which are somewhat forest-clad: the Mocajahi, south of the river of the same name and west of the Branco; the Moon, between the head of the Takutu and the Branco and the Kanuku, between the Rupiinuni and the Takutu. The latter forms a picturesque chain which continues in a broken series eastward to the Corentine.

The level plain is interrupted here and there by depressions which become shallow lakes in the rainy season. During the long dry season the waters evaporate and leave behind great meadows whose numerous narrow streams are lined with Eta palms which give character to the scenery. One of these depressions between the Rupununi and the Ireng was the mythical Lake Amucu on whose shore stood El Dorado, the Golden City of the Spaniards.

The rainfall amounts to sixty inches in the eastern savannah and only to forty-two in the western section.