My friends and me at Hadrian's wall.

Hadrian's Wall is a stone and turf fortification built by the Roman Empire across the width of what is now northern England. Begun in AD 122, during the rule of emperor Hadrian, it was the third of four such fortifications built across Great Britain, the first being from the River Clyde to the River Forth under Agricola and the last the Antonine Wall. All were built to prevent military raids on Roman Britain by the Pictish tribes (ancient inhabitants of Scotland) to the north, to improve economic stability and provide peaceful conditions in Britain, and to mark physically the frontier of the Empire. Hadrian's Wall is the best known of the three because its physical presence remains most evident today.

A significant portion of the wall still exists, particularly the mid-section, and for much of its length the wall can be followed on foot. It is the most popular tourist attraction in Northern England, where it is often known simply as the Roman Wall. =]