Titus Livius (Livy), The History of Rome, Book 26
D. Spillan, A.M., M.D., Cyrus Evans, Ed.

42. Having animated his troops with this harangue, and leaving Marcus Silanus with three thousand infantry and three hundred horse, for the protection of that district, he crossed the Iberus with all the rest of his troops, consisting of twenty-five thousand infantry and two thousand five hundred horse. [2] Though certain persons there endeavoured to persuade him that, as the Carthaginian armies had retired from each other into three such distant quarters, he should attack the nearest of them; yet concluding that if he did so there was danger lest he should cause them to concentrate all [p. 1076]their forces, and he alone should not be a match for so many, he determined for [3??] the present to make an attack upon New Carthage, a city not only possessing great wealth of its own, but also full of every kind of military store belonging to the enemy; there were their arms, their money, and the hostages from every part of Spain. [4] It was, besides, conveniently situated, not only for a passage into Africa, but also near a port sufficiently capacious for a fleet of any magnitude, and, for aught I know, the only one on the coast of Spain which is washed by our sea. No one but Caius Laelius knew whither he was going. [5] He was sent round with the fleet, and ordered so to regulate the sailing of his ships, that the army might come in view and the fleet enter the harbour at the same time. [6] Both the fleet and army arrived at the same time at New Carthage, on the seventh day after leaving the Iberus. The camp was pitched over against that part of the city which looks to the north. [7] A rampart was thrown up as a defence on the rear of it, for the front was secured by the nature of the ground. Now the situation of New Carthage is as follows: at about the middle of the coast of Spain is a bay facing for the most part the south-west, about two thousand five hundred paces in depth, and a little more in breadth. [8] In the mouth of this bay is a small island forming a barrier towards the sea, and protecting the harbour from every wind except the south-west. From the bottom of the bay there runs out a peninsula, which forms the eminence on which the city is built; which is washed in the east and south by the sea, and on the west is enclosed by a lake which extends a little way also towards the north, of variable depth according as the sea overflows or ebbs. [9] An isthmus of about two hundred paces broad connects the city with the continent, on which, though it would have been a work of so little labour, the Roman general did not raise a rampart; [10] whether his object was to make a display of his confidence to the enemy from motives of pride, or that he might have free regress when frequently advancing to the walls of the city.