The Big Dig : the excavation of the LEP tunnel was the most formidable civil-engineering venture in the history of CERN and Europe's largest civil-engineering project prior to the Channel Tunnel.

Siting a 27-km long underground ring in the corridor between the Jura mountains and Lake Geneva was no easy matter. After several proposals, the decision was made to install the ring along the foot of the Jura range. However, owing to geological features the tunnel had to be built on a gradient of 1.4 %, sloping towards the Lake.