A new art installation allows the public to see what a skyline without the much-detested Archway Tower would look like.

It has taken artist Ruth Ewan four years to create the optical illusion through a static viewing device which was unveiled near the corner of St John’s Grove in Holloway Road last week.

It allows users to see the area in real time but special “subtractive reality” computer software eradicates the skyscrapper, which is owned by Transport for London and is currently lying empty, from the field of vision.

Ms Ewan, 31, said: “People can see the traffic, the weather, the correct lighting conditions, but not the tower.

“It was great seeing people’s reactions when they weren’t expecting anything, and seeing how instantly the penny dropped. It’s such a local bugbear, it was great to see the little moment of magic when they realised the tower had disappeared.”

She developed the idea four years ago when she was working with Archway resident Fang Sang on at the Byam Shaw School of Art in Elthorne Road, Upper Holloway. He told her that he’d like to see the tower “disappear” and she set about trying to make it happen.

The installation forms part of the How to Make Archway Tower Disappear project, which also includes a book containing accounts of the tower from people who have worked in it, visited it, looked at it and considered its relationship to the place and people of Archway.

It’s fourth work commissioned by long-term objective Alight – a collaboration between Central Saint Martins College’s projects studio AIR and Islington Council’s arts service to find ambitious temporary works that explore, reveal and animate Archway.

Ms Ewan added: “It would be great if it prompted something useful to be done with the building as it’s just sitting completely empty.”

The viewer, which was supported by the Mayor of London’s Outer London Fund, is set to remain in situ for the next five weeks.