The enclosed shopping center, which would eventually be known as the shopping mall, did not appear until the mid-1950s. One of the earliest examples was the Valley Fair Shopping Center in Appleton, Wisconsin, which opened in March 1955. Valley Fair featured a number of modern features including central heating and cooling, a large outdoor parking area, semi-detached anchor stores, and restaurants. Later that year the world's first fully enclosed shopping mall was opened in Luleå, in northern Sweden (architect: Ralph Erskine) and was named "Shopping"; the region now claims the highest shopping center density in Europe.