The Art of War by active 6th century B.C. Sunzi

8. If forced to fight in a salt-marsh, you should have water and grass

near you, and get your back to a clump of trees. [Li Ch’uan remarks that the ground is less likely to be treacherous where there are trees, while Tu Mu says that they will serve to protect the rear.] So much for operations in salt-marshes.