year, only when the natural ice along the entire course is at least thick. It is sometimes held on consecutive years, while at other times, gaps between the touring years have exceeded 20 years. When the ice is suitable, the tour is announced and starts within 48 hours. The last Elfstedentocht was held in 1997. Laneways The sports of curling and Ice stock sport are played on either ice rinks or simple ice surfaces with lanes marked out for play. Curling The sport of curling uses an ice rink known as a "curling rink" or curling sheet. Curling does not involve ice skating. Curling uses lanes. The curling sheet is a carefully prepared rectangular area of ice created to be as flat and level as possible. The ice surface dimensions are in length by in width. A curling sheet includes areas marked off in a manner specific to the sport, including the house, the button, hog lines, hacks, and shorter borders along the ends of the sheet called the backboards. The dimensions of an official curling sheet is defined by the World Curling Federation Rules of Curling. At major events, ice preparation and maintenance is extremely important. Curling clubs usually have an ice maker whose main job is to care for the ice. Other Crokicurl Crokicurl is a Canadian winter sport and is a large scale hybrid of curling and the board game Crokinole. It is played outdoors by teams consisting of two players who take turns trying to score points on a quadrant shaped area with the playing area marked off on a sheet of ice. The quadrant includes posts, starting line, wooden edge side-rail, and a 20-point "button". Depending on the area involved, players can score 5, 10, or 15 points. Outdoor ice Outdoor ice rinks and frozen ponds, rivers, and canals, serve several purposes, allowing for physical activities during the winter season such as recreational ice skating and figure skating, and also function as an affordable place for players to engage in team winter sports such as ice hockey, bandy, rinkball, ringette, broomball, and spongee, as a pastime. These areas and facilities also help individuals, youth sporting organizations, and families, offset the expensive cost of indoor ice-time. They are also used as a part of outdoor winter festivals and to host pond hockey tournaments and the like. Decline Rinks The length of outdoor ice skating season began