Rock Crawling is a form of off road driving that can range from driving over small bolder to extreme size bolder and walls of rocks.
Wikipedia defines Rock Crawling as:
Rock crawling is an extreme form of off road driving
Rock crawling is an extreme form of off road driving using vehicles anywhere from stock to highly modified to overcome obstacles. In rock crawling, drivers drive highly modified four-wheel-drive vehicles such as trucks, Jeeps, and “buggies” over very harsh terrain. Driving locations include boulders, mountain foothills, rock piles, mountain trails, etc.
Rock crawling is about slow-speed, careful and precise driving, and high torque generated through large gear reductions in the vehicles drivetrain. Rock crawlers often drive up, down and across obstacles that would appear impassable. Such vehicles to rock climb are primarily 4x4s.
Rock crawling competitions range from local events to national series. A rock crawling competition consists of obstacle courses that are about 100-200 yards long. Each obstacle is set up with gates, similar to a ski course.