Artists will use 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 organisers of the London 2012 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 wall, which snakes across hill and dale in northern England just south of the Scottish border.

The balloons will be fitted with lights and networked so they can communicate with one another. Viewers will be able to submit short messages which will be transformed into pulses of colored light that pass along the wall in patterns reminiscent of Morse Code.

Group member Zachary Lieberman, who is overseeing final work on the project at Newcastle University in northeast England, said today he hoped to create "the inverse of a border ... to imagine the border as a means of connection" rather than separation.

He said balloons were chosen for their ability to evoke a sense of wonder and magic.

The work will be staged the nights of 31 August and 1 September. Visitors will be able to see stretches of the wall from spots along the route, while people around the world can watch on the Internet.

The London 2012 Festival is a three-month, cross-country arts extravaganza of 12,000 events staged to coincide with the Olympic and Paralympic Games.

Events have ranged from a touring inflatable replica of the ancient Stonehenge monument to the world premiere of Karlheinz Stockhausen's opera "Mittwoch aus Licht" — which features a string quartet playing from four airborne helicopters — to a mass nationwide bell-ringing to mark the start of the Olympics on July 27.

The festival ends on 9 September, coinciding with the end of the Paralympics.