Swiss engineers broke through a final 180 centimetres of rock deep in the Alpine mountains on Friday, linking the world's longest tunnel, DPA reported.
The 57-kilometre Gotthard Base Tunnel will be used for transport through the Alps.
The ceremony to mark the event, after ten years of construction, started at 1pm local time and the breakthrough took place at 217pm, the Swiss SDA news agency reported.
The tunnel is expected to open for business, including passenger and freight trains, in 2017.