CERN has carried out over a number of years a detailed study on the possibility of adding a set of Intersecting Storage Rings (ISR) to its 28 GeV Proton Synchrotron. The plans presented by CERN were accepted by the CERN Council at its meeting in June 1965 and the necessary funds for the construction were allocated in December of the same year. The ISR will consist of two concentric magnet rings of about 150 m mean radius. The two rings are slightly distorted so as to cross each other at 8 points, around which the colliding beam experimentation will take place. With about 20 A of stacked protons in each ring, the interaction rate will be about 1.5 × 105 interactions/sec. in each of the crossing points. The construction has started and the lecture will give a description of the project and its present status. It is hoped that the runningin of the facility will start in 1971.