The physical characteristics of Vietnamese jungles created tactical challenges that negated many of the technological advantages that American forces possessed over their enemies, as the thick canopy of leaves and branches blocked aerial observation while providing perfect concealment for enemy forces who understood how to use the terrain to their advantage. The multiple layers of vegetation, from towering hardwood trees that blocked sunlight to dense understory growth that reduced visibility to a few feet, created an environment where traditional military formations and movement techniques became not only ineffective but dangerous. The maze-like quality of jungle terrain made map reading and navigation extremely difficult even for experienced soldiers, while the absence of recognizable landmarks or clear sight lines meant that units could become lost within yards of their intended routes.