Although Fort Duquesne's location at the forks looked strong on a map—controlling the confluence of three rivers—the reality was rather different. The site was low, swampy, and prone to flooding. In addition, the position was dominated by highlands across the Monongahela River, which would allow an enemy to bombard the fort with ease. Pécaudy de Contrecœur was preparing to abandon the fort in the face of Braddock's advance in 1755. He was able to retain it due to the advancing British force being annihilated (see below). When the Forbes expedition approached in 1758, the French had initial success in the Battle of Fort Duquesne against the English vanguard, but were forced to abandon the fort in the face of the much superior size of Forbes' main force.