Slalom courses are usually on Class II - IV whitewater. Some courses are technical, containing many rocks. Others are on stretches containing fewer rocks and larger waves and holes. Slalom canoeing made its Olympic debut in 1972 in Augsburg, W. Germany. It was not seen again until 1992 in Seu d'Urgell as part of the Barcelona games. Since then, slalom paddling has been a regular at the Olympics. The 1972 Olympics in Augsburg were held on an artificial whitewater course. The Augsburg Eiskanal set the stage for the future of artificial course creation. With the exception of the altered river bed of the Ocoee River in 1996, every Olympic venue has been a man-made concrete channel. Since the late 80s, artificial course creation has surged; now most countries that field Olympic slalom teams have more than one artificial course to train on. Artificial river creation has evolved and new courses have fewer issues than the some of the initial designs. Artificial rivers / creeks offer a controlled environment that offers a more consistent field of play for slalom racers and better viewing for spectators. However, natural river courses are still utilized in many national and international slalom races throughout the world.