Sergeant David Wilkes, of the First (Royal) Regiment of Foot—third battalion, B Company—came trudging with a small fatigue party down the sandy slopes of Mount Olia, on the summit of which they had been toiling all day, helping the artillerymen to drag an extra 24-pounder into battery. They had brought it into position just half an hour ago, and already it had opened fire along with another 24-pounder and two howitzers mounted on the same rocky platform. The men as they descended heard the projectiles fly over their heads, and paused, distinguishing the scream of the shells from the dull hum of the round-shot, to watch the effect of the marksmanship, which was excellent.
Northwards, to their right, stretched the blue line of the Bay, where a single ship-of-war tacked lazily and kept a two-miles’ offing. The smoke of the guns, drifting down on the land-breeze from the summit of Mount Olia, now hid her white sails, now lifted and revealed them in the late afternoon sunshine. But although blue held the upper heavens—cloudless blue of July—the sunshine that reached the ship was murky, almost copper-coloured; for it pierced through a cloud of denser smoke that rolled continuously along the western horizon from the burning houses of San Sebastian.
Sergeant Wilkes and his men, halting on the lower slope of the mountain where it fell away in sand-dunes to the estuary of the Urumea, had the whole flank of the fortress in view. Just now, at half-tide, it rose straight out of the water on the farther bank— a low, narrow-necked isthmus that at its seaward end climbed to a cone-shaped rock four hundred feet high, crowned by a small castle. This was the citadel. The town, through which alone it could be taken by force, lay under it, across the neck of the isthmus; and this again was protected on the landward side by a high rampart or curtain, strengthened by a tall bastion in its centre and covered by a regular hornwork pushed out from its front. So much for the extremities, seaward and landward. That flank of the place which it presented to the sandhills across the Urumea was clearly more vulnerable, and yet not easily vulnerable. Deep water and natural rock protected Mount Orgullo, the citadel hill. The sea-wall, for almost half its length, formed but a fausse braye for the hornwork towering formidably behind it. Only where it covered the town, in the space between citadel and hornwork, this wall became a simple rampart; stout indeed and solid and twenty-seven feet high, with two flanking towers for enfilading fire, besides a demi-bastion at the Mount Orgullo end, yet offering the weak spot in the defences.