Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Wirral or the Wirral is a peninsula in North West England. It is bounded to the west by the River Dee, which forms the boundary with Wales, and to the east by the River Mersey. Both terms "Wirral" and "the Wirral" are used locally (and interchangeably), although the merits of each form are the subject of local debate. The roughly rectangular peninsula is about 10 miles (16.1 km) long and 7 miles (11.3 km) wide. Under the Local Government Act 1972 the northern part constitutes the Metropolitan Borough of Wirral in Merseyside, and the southern part is administered as part of Cheshire West and Chester.