The extreme left was on the Jaizquibel. This narrow mountain ridge, seventeen hundred feet high, runs along the coast, abutting at one end upon the Passages harbour and at the other upon the navigable mouth of the Bidassoa. Offering no mark for an attack it was only guarded by a flanking detachment of Spaniards, and at its foot the small fort of Figueras commanding the entrance of the river was garrisoned by seamen from the naval squadron. Fuenterabia a walled place, also at its base, was occupied, and the low ground between that town and Irun defended by a chain of eight large field redoubts, which connected the position of Jaizquibel with the heights covering the royal road to Oyarzun. On the right of Irun, between Biriatu and the burned bridge of Behobia, there was a sudden bend in the river, the concave towards the French, and their positions commanded the passage of the fords below; but opposed to them was the exceedingly stiff and lofty ridge, called San Marcial, terminating one of the great flanks of the Pena de Haya. The water flowed round the left of this ridge, confining the road leading from the bridge of Behobia to Irun, a distance of one mile, to the narrow space between its channel and the foot of the height, and Irun itself, strongly occupied and defended by a field-work, blocked this way. It followed that the French, after forcing the passage of the river, must of necessity win San Marcial before their army could use the great road. About six thousand men of the fourth Spanish army now under general Freyre, were established on the crest of San Marcial, which was strengthened by abbattis and temporary field-works. Behind Irun the first British division, under general Howard, was posted, and lord Aylmer’s brigade was pushed somewhat in advance of Howard’s right to support the left of the Spaniards. The right of San Marcial falling back from the river was, although distinct as a position, connected with the Pena de Haya, and in some degree exposed to an enemy passing the river above Biriatu, wherefore Longa’s Spaniards were drawn off from those slopes of the Pena de Haya which descended towards Vera, to be posted on those descending towards Biriatu. In this situation he protected and supported the right of San Marcial.