LONDON.- Graffiti artist Banksy has turned a south London tunnel into a half-mile long exhibition space, but the elusive artist kept its location secret until the last minute, reported the BBC. Banksy marshaled more than three dozen international artists for what he's calling the "Cans Festival" — and is encouraging visitors to contribute their own graffiti starting Saturday.

Members of the public are being invited to take part in Banksy's latest project in London, as an army of graffiti writers turn a whole street into an art exhibition. The organizers' Web site (www.thecansfestival.com) makes the "rules of engagement" clear:

* no freehand lettering or characters may be sprayed on to the tunnel walls, and stencils must be employed

* artists must report to reception on arrival and they will be told where to paint

* artists must not spray over works already on the walls.

A mix of installations, sculptures and stencils has transformed the normally drab and dank street between York Street and Lower Marsh.

Cans Festival is being sponsored by Picturesonwalls, that East End shop that sells prints by Banksy and other street artists. While Banksy has said that he hopes the spectacle will be a long-term installation, it’s only guaranteed to be around from 10am Saturday until 10pm Monday.