Morgan's first action was to take the connected islands of Old Providence and Santa Catalina in December 1670. From there his fleet sailed to Chagres, the port from which ships were loaded with goods to transport back to Spain. Morgan took the town and occupied Fort San Lorenzo, which he garrisoned to protect his line of retreat. On 9 January 1671, with his remaining men, he ascended the Chagres River and headed for Old Panama City, on the Pacific Coast. Much of the journey was on foot, through dense rainforests and swamps. The governor of Panama had been forewarned of a potential attack, and had sent Spanish troops to attack Morgan and his men along the route. The privateers transferred to canoes to complete part of the journey, but were still able to beat off the ambushes with ease. After three days, with the river difficult to navigate in places, and with the jungle thinning out, Morgan landed his men and travelled overland across the remaining part of the isthmus.