Epsom (/ˈɛpsəm/) is a suburban market town in the borough of Epsom and Ewell in Surrey, England. Small parts of Epsom are in the Mole Valley District and Borough of Reigate and Banstead. The town is 13.6 miles (21.9 km) south south-west of Charing Cross, within the contiguous urban area of London mapped by the Office for National Statistics. The town straddles chalk downland (topped by the Epsom Downs part of the North Downs) and the upper Thanet Beds. The eponymous racecourse at its edge holds The Derby at the start of summer which has become the generic name for a major annual competition across many sports in English-speaking countries. The town also gives it name to Epsom Salts which were identified from mineral waters there.