Engineers have drilled through the last remaining rock to complete the world's longest tunnel, under the Swiss Alps.
A 10-metre diameter drill-head tore through the rock to cheers and applause 2,000m underground.
The 57km Gotthard rail tunnel has taken 14 years to build and is not likely to open before the end of 2016. It is costing 9.8 billion Swiss franc ($US10.3 billion).
The BBC reports it is expected to revolutionise transport across Europe, providing a high-speed link between the north and south of the continent.
Eventually, trains will travel through it at speeds of up to 250km/h.
Journey times between Zurich and Milan are likely to be slashed by as much as an hour and a half.
The event, which took place shortly after 2.15pm (1215 GMT) on Friday, was broadcast live on Swiss TV.
The tunnel will take up to 300 trains each day underneath the Alps.
Its length exceeds the 53.8km Seikan rail tunnel linking the Japanese islands of Honshu and Hokkaido and the 50km Channel tunnel linking England and France.