Today Poole Harbour's beaches and islands make it a tranquil haven for weekend sailors, walkers and swimmers. But in the Iron Age it was a thriving port - perhaps the most important in the country, trading all sorts of goods with the continent.

But was it also an industrial heartland? Tony Robinson takes the boat to Green Island in the centre of the harbour to investigate what might have been a site of early mass production.

The finds come thick and fast and the Team need every minute of their three days to come up with an answer.