We set sail from a German city for today's Geo Quiz. Ships have been making stops in the German port we're looking for today...as far back as the 12th century.

The city's located at the spot where the river Weser empties into the North Sea. Nowadays this city is one of Germany's busiest ports.

More than 3-and-a-half-million cargo containers are shipped out from here each year. One merchant ship just headed out of the harbor with a load of cargo.

“The empty vessel weighs around 3,000 tons and at the moment we have around 10,000 tons including the cargo.”

We'll hear more from that ship captain on the next page. His vessel is trying out a new technology to reduce fuel costs and carbon emissions.

“It's a simple device really... It's a big kite!”

We'll tell you more about this kite-powered cargo-ship. But first try and name this northern German seaport.