On the 18th the wind shifted again, and blowing strongly from the west, piled the sea against the dams. With the rising water level, the flotilla was soon able to make a circuit around the bridge and canal, and successfully enter the Zoetermeer. In October, the Dutch patriots led by William the Silent destroyed the dykes in 4 locations in order to form an obstacle the Spanish troops could not overcome. As a result of this and the coming of a strong wind from the West, the water rose and Spanish troops lost their mobility. On one of these 4 locations, a monument has been established in remembrance of what happened called the Groenedijk Monument. The Sea Beggars had ships to successfully use the water to their advantage. A succession of fortified villages now stood in the way of the patriot fleet, and the Dutch Admiral was afraid even now of losing his prize, but the Spaniards, panicked by the rising waters, barely offered any resistance. Every one of their strongholds, now become islands, were deserted by the Royalist troops in their flight, except for the village of Lammen. This was a small fort under the command of Colonel Borgia, and situated about three-quarters of a mile from the walls of Leiden.