Even more important than Peniche was Abrantes, the one great crossing-place of the Tagus above Lisbon where there was a permanent bridge, and free communication by good roads between Beira and Alemtejo. It lies at the point where the road from Spain by way of Castello Branco crosses the road from north to south down the Portuguese frontier, from Almeida and Guarda to Evora and Elvas. An invader who has advanced towards Lisbon through Beira has it on his flank and rear, equally so an invader who has advanced on the same objective from Badajoz and the Guadiana. It is the natural point at which to move troops north and south along the frontier, though Wellington had established an alternative temporary crossing-point at Villa Velha, thirty miles higher up the river, by means of pontoons. But this secondary passage was inferior in safety, since it was not protected by a fortress like Abrantes. Orders were given to burn the pontoons if ever a French force from the East should came near. At Abrantes, on the other hand, the boat-bridge could be pulled up and stacked under the city walls in the event of an attack, and did not need to be destroyed. The town is situated on a lofty eminence upon the north bank of the Tagus. Its fortifications were antiquated in 1809, but had been for many months in process of being rebuilt and strengthened by the English engineer Patton. With new earthworks and redoubts it had been made a strong place, which could not be taken without a regular siege and plenty of heavy artillery. Here Wellington had placed a garrison of two militia regiments under the Portuguese general Lobo, whose orders were to resist to the last, and to make sure of burning the boat-bridge, down to the last plank, before surrendering. The French never put him to the test, since they had no heavy guns with them, and therefore regarded it as hopeless to attempt an attack on the place[199]. [199] D’Urban has a long disquisition on Abrantes in his diary. Its weak points, he says, were an outlying hill on the Punhete road, which gave a favourable position for hostile batteries, and the friable nature of the gravelly soil, which did not bind well in trenches and outworks.