town, Sefton metropolitan borough, metropolitan county of Merseyside, historic county of Lancashire, England. It is a residential community and Irish Sea coastal resort about 20 miles (32 km) north of the major port of Liverpool. It grew rapidly in the 19th century on coastal dunes, with spacious gardens and golf courses, including Royal Birkdale. These amenities lie along the seafront and the shopping thoroughfare, Lord Street. Pop. (2001) 91,404.