By the 17th century Daniel Defoe described Smithfield, in London, as the greatest meat market in the world. In 1855 it was moved to the outskirts of the city, to a site known as the Caledonian Market on Caledonian Road, Islington, to avoid the problems of large numbers of stock being driven through the streets. Cattle were also driven to other major cities, to areas of intermediate grazing to be fattened for market, and to markets and fairs. Many of the greatest stock fairs, such as Tan Hill, Yarnbury and White Sheet in Wiltshire, were held on ancient sites to which cattle were driven for centuries, perhaps since prehistoric times.