Lempa, a river of San Salvador, and the largest stream of Central America falling into the Pacific. It rises in the lake of Guija, in the N. W. corner of San Salvador, flows nearly due E. through a broad and fertile valley for a distance of nearly 150 m., and then, turning abruptly S., breaks through the volcanic coast range of mountains, and falls into the Pacific in lat. 13° 22' N., Ion. 88° 12' W. For a considerable part of its course it is navigable. It drains a wide expanse of country, has numerous large tributaries, and as a consequence is subject to sudden floods, at which times the water rises on the lower portions of the stream from 20 to 35 ft., completely submerging the neighboring country. The mouth of the river, which is broad and open, is obstructed by a bar with only 6 ft. of water; but the estero of Jaltepeque approaches to within a league of the river, with which it is connected by a natural channel, navigable by small boats during the rainy season.