A helter skelter is a funfair or amusement park ride with a slide built in a spiral around a high tower. Users climb up inside the tower and slide down the outside, usually on a mat or hessian sack. Typically the ride will be of wooden construction and, in the case of fairground versions, designed to be disassembled to facilitate transportation between sites. The term is primarily (but not exclusively) found in English. In the US, they are called a "tornado slide".