A hairpin curve is a sharp bend in a road, which can pose a challenge for drivers. Synonyms for this challenging feature include switchback, bend, winding, turn, twist, and meander. A switchback is typically a steep and narrow section of road that zig-zags back and forth up a mountainside. A winding road may have gentle turns that alternate between left and right as it follows its natural path around hills and valleys. A turn or twist can also be used to describe a sudden change in direction, sometimes coupled with a change in elevation. Meandering roads may follow a river or undulating terrain with a gentle, curving path.