Returning to Cartagena, Heredia fell in with a vessel newly arrived from Española with troops on board that raised his command to one hundred foot and as many horse. Thus reënforced, he penetrated the province as far as the town of Cenú, in the valley of a river which still bears that name. Here was found in two boxes or chests gold to the value of 20,000 pesos, and in a place which went by the name of "El bohío del diablo,"[II‑5] a pit with three compartments, each about two hundred and fifty feet in length, was a hammock supported by four human figures, and containing gold to the value of 15,000 pesos, amid which, according to Indian tradition, his sable majesty was wont to repose. In a sepulchre near by, gold-dust was unearthed to the amount of 10,000 pesos. Well satisfied with the results of his expedition Heredia returned to head-quarters, and was soon afterward joined by a fresh reënforcement of three hundred men. The tidings of his success soon attracted numbers of dissatisfied colonists from Castilla del Oro, and toward the close of the sixteenth century Cartagena became a place of considerable note,[II‑6] the fleet that supplied the New World with the merchandise of Spain touching there on the way to Portobello. The latter was but a small village, tenanted chiefly by negroes, and possessing, next to Nombre de Dios, the most sickly climate of all the settlements in Tierra Firme. So deadly were the exhalations from its rank and steaming soil that a small garrison maintained there to guard the fleet was changed four times a year. Notwithstanding its unwholesome atmosphere an annual fair was held there lasting forty days, during which time its streets were crowded with merchants from every quarter of the Indies. Not many years afterward the Peruvian herder, climbing the mountain side in quest of his stray llama, discovered the silver-mines of Potosí,[II‑7] and the place became, for a few weeks in the year, the most redundant mart of commerce in the world. A fleet, freighted with all that was required to supply the real and artificial wants of an opulent community, called there once a year, and as soon as it appeared in sight the treasures of the mines and pearl-fisheries were conveyed by land from Panamá to Cruces, and thence down the Rio Chagre to Portobello. [Illustration: CASTILLA DEL ORO.] [Sidenote: SAN SEBASTIAN.]