Stratford International railway station foundation under construction in London, part of the Channel Tunnel Rail Link (CTRL). This vast concrete structure is called the Stratford Box". The railway link runs between this London station of Stratford and St. Pancras International (at King's Cross). From here twin tunnels of this rail link stretch 7.5km under London to form Britain's first high-speed railway that will carry Eurostar Channel Tunnel trains into and out of London. Photographed in early 2004."