LONDON (AP) - A group of American artists is using 450 balloons and thousands of light emitting diodes to turn the 2,000-year-old Hadrian's Wall into the world's longest work of art.

New York digital arts collective YesYesNo has been invited by organizers of Britain's Olympic-themed summer arts festival to transform the wall, built by Roman invaders to guard the northern frontier of their empire.

"Connecting Light" will suspend hundreds of white weather balloons above the 73-mile (117- kilometer) wall, which snakes across northern England south of the Scottish border.

Group member Zachary Lieberman said Tuesday he hoped "to imagine the border as a means of connection" rather than separation.

The work will be staged Aug. 31 and Sept. 1 as part of the London 2012 Festival.