The biggest block of stone ever to leave the Dorset island of Portland made its way across the causeway to the mainland on 10 July at the start of a three-day journey to the Summer Arts Programme at Compton Verney in Warwickshire.

The artist responsible for the movement of the 100-tonne block of stone was John Frankland, one of three artists taking part in the programme that takes passage and routes as its theme.

The progress of the stone from Portland to Compton Verney, using three police escorts as the lorry made iuts way through three counties, was all part of the piece of art.

Once at the 18th century Compton Verney mansion the stone was up-ended in the front lawn, where its stand about 4.5m high. Climber Johnny Dawes created routes over it so that visitors were able to interact with it by climbing on it.

The stone is not actually the famous Portland limestone that has been used to build so much of London, as well as prestigious buildings elsewhere in the country. It is the cap stone that sits over the Portland stone itself and is usually blasted off and crushed for aggregates.

Hanson donated the massive piece of stone to the Summer Arts Programme, although it was down to the organisers to hire the cranes and haulage to get it out of Coombefield Quarry - which cost about £10,000.

It took two big cranes to lift the block on to the lorry and even bigger cranes to lift it off at the other end so it could be stood on its end.

And in spite of the effort of getting the block into the exhibition, it cannot stay there. When the programme comes to an end later in the summer it has to be moved because it only has temporary planning permission. Nobody is quite sure where exactly it will go. It may be moved from the front lawn to a more inconspicuous site at the mansion. A local climbing club have also shown some interest in having it for practice, although whether they could afford to move it and where they would put it are questions that are so far unanswered.