Swiss engineers drilling the world's longest tunnel broke through the last section of rock on Friday, crowning over a decade of work.
The 57.1-km (35.5-mile) rail tunnel under the Gotthard massif will enter service in 2017, taking some of the strain of the tens of thousands of tonnes of freight that cross the Alps on heavy goods trucks by road every day.
A 10-meter wide rotary drill ceremonially ground away the last centimeters of rock at an event broadcast live on Swiss television.
"Together we risked a lot. Together we achieved a lot, because we know the mountain is large but we are small," said Swiss Environment and Transport Minister Moritz Leuenberger.
The project is costing more than 12 billion Swiss francs ($12.58 billion), and has claimed the lives of eight construction workers.