In the context of terrain flying, which of the following is NOT a major terrain feature?

In the context of terrain flying, valleys, depressions, and hills are all major terrain features that significantly influence flying techniques and approaches. Cliffs, while prominent and potentially hazardous, are not typically categorized in the same way as the others when discussing major terrain features that affect flight paths and navigational strategies.

Valleys can create low-level flying challenges due to turbulence and concealment, making them important to recognize. Depressions can represent areas where aircraft may have to adjust altitude to avoid potential hazards or to respond to changing weather conditions. Hills are prominent landforms that can affect visibility and require careful navigation to avoid collisions.

Cliffs, while significant, are often viewed more as individual vertical landforms rather than as part of broader landscape categories that pilots routinely plan for. Thus, they can be seen as less fundamental in the context of strategic terrain navigation compared to valleys, depressions, and hills, which play more direct roles in overall terrain evaluation and flying operations.