Funded by consortium led by Richard Branson, a weir is built between Gibraltar and Morocco. It is the world's largest dam and it prevents the water in the Mediterranean Sea from rising, saving Venice, Cyprus an countless coastal areas from flooding. The Alboran Weir also controls the flow between the Atlantic and Mediterranean sustaining the Gulf Stream and preventing the freezing of Europe. Visitors flock to the weir. At the information centres they learn how they can each contribute to preventing environmental disaster.