9. The Army on the March
15
Country in which there are precipitous cliffs with torrents running between, deep natural hollows,
The latter defined as "places enclosed on every side by steep banks, with pools of water at the bottom.
confined places,
Defined as "natural pens or prisons" or "places surrounded by precipices on three sides—easy to get into, but hard to get out of."
tangled thickets,
Defined as "places covered with such dense undergrowth that spears cannot be used."
quagmires
Defined as "low-lying places, so heavy with mud as to be impassable for chariots and horsemen."
and crevasses,
Defined by Mei Yao-ch`en as "a narrow difficult way between beetling cliffs." Tu Mu's note is "ground covered with trees and rocks, and intersected by numerous ravines and pitfalls." This is very vague, but Chia Lin explains it clearly enough as a defile or narrow pass, and Chang Yu takes much the same view. On the whole, the weight of the commentators certainly inclines to the rendering "defile." But the ordinary meaning of the Chinese in one place is "a crack or fissure" and the fact that the meaning of the Chinese elsewhere in the sentence indicates something in the nature of a defile, make me think that Sun Tzu is here speaking of crevasses.