PLAYERS of an internet treasure hunting craze known as geocaching are believed to be climbing York’s historic buildings searching for prizes.

The game, which has become a worldwide phenomenon, involves players searching for tiny hidden prizes, left by other players, with the help of their mobile phone’s global positioning system.

Some players, however, have been attempting to climb drainpipes attached to historic buildings in Shambles in the mistaken belief that the tiny prizes have been hidden in wooden beams.

Matt Johnson, of Cox’s of Shambles, said he had been forced to put a sign on a drainpipe next to the shop several months ago, after geocachers attempted to climb up it, mistakenly thinking a prize was hidden nearby.

“The geocache created for that one was wrong,” he said. “They said it was in our passage and it wasn’t, but there were people climbing the drainpipe and they couldn’t find it. They were climbing on the roof trying to find it.”

He said the prize was actually hidden in another passage next to the Mr Sandwich shop.

According to geocaching.com, the world’s biggest website on the craze, there are rules on where the objects should be placed and it is recommended that historic buildings are avoided.

The site advises: “In most cases these areas are highly sensitive to the extra traffic that would be caused by vehicles and humans.”

The geocaching craze has caught on in many countries around the world. The caches, which can be anything from a simple greeting and a form for the finder to sign, can be hidden anywhere.

The co-ordinates are put on the internet by the person who hides the cache and people then use their GPS or smartphone to get to the approximate location before searching for the hidden prize.