Green Island in Poole Harbour has already shown that it was a significant centre of Iron Age activity, with evidence of industrial activity and trading to and from the continental mainland. But it has never been properly excavated. Two huge jetties - now buried - indicate either a port or a defensive structure. The island is a SSSI (Site of Special Scientific Interest), which means hand-digging only, and replacing the topsoil. Very soon the finds start to multiply. Of particular interest is evidence of shale working for jewelry, and iron smithing. They are joined by Project Director Eileen Wilkes, archaeologist Miles Russell, Iron Age specialist John Collis, and metallurgist Roger Doonan. Experimental archaeologist Jake Keenan demonstrates shale working with primitive tools. Geomorphologist Vincent May explains that in prehistoric times the water level was two metres lower, and Green Island was much bigger.

• Tim Taylor

• Tony Robinson
• Bill Oddie
• Phil Harding