Petroleum has been found at several points on the coast in the department of Piura, and near Lake Titicaca in the department of Puno.
In 1889 the total foreign debt, including arrears of interest, was £54,000,000, and in the following year a contract was signed with the Peruvian Corporation, a company in which the bondholders became shareholders, for the transfer to it for 66 years of the state railways,, the free use of certain ports, the right of navigation on Lake Titicaca, the exploitation of the remaining guano deposits up to 3,000,000 tons, and thirty-three annual subsidies of £80,000 each, in consideration of the cancellation of the debt.
The conquering tribe or tribes had made their way to the sierra from the plains, and found themselves a new land sheltered from attack amidst the lofty mountains that hem in the valley of Cuzco and the vast lake basin of Titicaca, situated 12,000 ft.
It is traversed by an important railway line from Mollendo (Islay) to Puno, on Lake Titicaca, 325 m.
The fact remains, however, that the curious metal-craft of the narrow strip along the Pacific from Mexico to Titicaca is the greatest of archaeological enigmas.