The Gotthard Base tunnel is the principal item of the new railway alpine transversal (NEAT). It consists of two one-way tunnels, 57 km long, linking Erstfeld (UR) and Bodio (TI). Technical equipment is placed in the cross adits which provide links to the opposite tunnel every 325 m.. In order to reduce the construction time, the headings have been excavated from the two portals and three intermediate adits: Amsteg adit (1782 m), Faido adit (2646 m) and Sedrun shaft (800 m deep). The tunnel mainly crosses crystalline rocks and some sections of sedimentary rocks. The main sedimentary rocks are in the Tavetscher intermediate mass and in the Piora-Mulde. The tunnel overburden reaches 2'300 m at the Gotthard-Massif. The excavation methods were carefully analysed, considering geology, geotechnics, composition of the lots, progress rates, construction costs, recycling of mined debris etc. More than 80 percent of the tunnel length is excavated using open Gripper TBMs. The horseshoe-shaped access tunnels were excavated by drill and blast. Two multifunction facilities have been built at the bottom of the shaft of Sedrun and at the underground end of the Faido adit. These will allow for emergency stop of the trains and the passengers rescuing. Furthermore, in these facilities are placed the technical rooms and the electromechanical main facilities of the tunnel. At the Bodio portal, the excavated material was brought to the “Buzza di Biasca” discharge by a TBM excavated transportation tunnel Ø=5.00 m, L=3'162 m. Great importance was given to the protection of the environment.