Ultra4 is a type of off-road racing that combines elements of rock crawling and high-speed desert racing. It features vehicles designed to tackle rugged terrains, including rocks, mud, and sand. Races often take place in challenging environments, testing both driver skill and vehicle durability. The most famous event in Ultra4 racing is the King of the Hammers, held annually in Johnson Valley, California. This event attracts competitors from around the world, showcasing custom-built vehicles that can handle extreme conditions. The races emphasize teamwork, strategy, and engineering prowess, making it a unique motorsport experience.