Curling was originally played out of doors on whatever frozen surface was available, was good enough, and was large enough - the playing surface is about 148 feet in length and 15 feet in width. Today, the game is played indoors in curling rinks. Most of these are private clubs, although some smaller communities operate public rinks. A rink has several sheets of ice, separated by low dividers, which allows several games to be played simultaneously. In smaller communities, the ice will be frozen naturally. This is a cheap way to make ice in a Saskatchewan winter. Clubs in larger towns and in cities (i.e., more members) install ice-making equipment. This is also needed where the winter is not cold enough for a long enough period of time to allow a reasonable number of games over the winter. It is, after all, a winter sport. Spectators are usually not allowed near the ice, where they could interfere with the game, unless there is no other place for them to sit. Most rinks have windows along one end of the ice area, which allows spectators the comfort of sitting in a warm environment, while keeping crowd noise away from the players.