More than 28 million tonnes of rock has been shifted to make the Gotthard Base Tunnel – the same amount of material needed to make six Great Pyramids of Giza. But the Swiss have instead used the material for various projects, including artificial islands.
A lot of the work was done by Sissi, Heidi and Gabi, the names given by the miners to the huge tunnel-boring machines that carved out the new Gotthard tunnel.
28 million tonnes is a lot of rock. What has been done with it?