Here the stream is rapid and difficult of passage, its bed being thickly studded with great boulders brought down in time of flood from the mountains.

The country on each side of the river is sandy, free from forests or valleys, which would cover the movements of an army.
The host gathered to oppose the Carthaginians were fully one hundred thousand strong, and Hannibal saw at once that his force, weakened as it was with its loss at Salamanca, and encumbered by the great train laden with the booty they had gathered from the Vacaei, would have no chance whatever in a battle with so vast a body.

The enemy separated as he approached the river, their object being evidently to fall upon his rear when engaged in the difficult operation of crossing.

The Carthaginians moved in two heavy columns, one on each side of their baggage, and Hannibal's orders were stringent that on no account should they engage with the enemy.
The natives swarmed around the columns, hurling darts and javelins; but the Carthaginians moved forward in solid order, replying only with their arrows and slings, and contenting themselves with beating off the attacks which the bolder of their foes made upon them.

Night was falling when they arrived on the bank of the river.