A rock cannon (known as ‘carreg cannan’ in Welsh) is an 18th-century firework tradition from Wales that is mostly forgotten today. Rock cannons were popular at any major festivity at the time, but the tradition was abandoned in the 20th century. A rock cannon is a rock bored with holes and tracks. The tracks were loaded with black powder and then ignited, which created a path of fire and explosions. Does this sound like fun? Then watch this cool video that tries to recreate this old Welsh tradition.