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

Chapter X. TERRAIN

[Only about a third of the chapter, comprising §§ 1-13, deals with "terrain," the subject being more fully treated in ch. XI. The "six calamities" are discussed in §§ 14-20, and the rest of the chapter is again a mere string of desultory remarks, though not less interesting, perhaps, on that account.]