Rugged rock face

CRAG

Think of a steep, jagged cliff often found in mountainous areas, where climbers might test their skills. It starts with the same letter as "cliffside."

"Rugged rock face" points to "CRAG," a word for a steep, jagged cliff or rocky outcrop often found in mountainous areas. The clue is straightforward with no wordplay—it directly describes the terrain feature. Think of hiking trails or climbing spots where you’d see these sharp, uneven rock formations. The answer fits because "crag" is the precise term for that kind of harsh, rocky surface.