The ring of Collision of Orsay was the first collider built in France. During your visit, you will be able to see the accelerator in its large hall(market) of origin, and the writing desks of the room of control of the big(great) linear accelerator. The museum also counts in its permanent collection, a retort(replica) as before of one of the first detectors installed(settled) on ACO, as well as a line of light. These unique(only) objects illustrate two manners to use particle accelerators. They give us to understand(include) the current generation of the very big(great) scientific instruments to which they gave birth(rise), as LHC in CERN in Geneva and the synchrotron SUN near(about) the University. For the school, visits are guided by professionals (researchers, technicians) who work or worked such in the domains of physics and of its instrumentation as they were practised to ACO. In family or in group, connoisseurs or greenhorns, come meet the living witnesses(batons) of this extraordinary adventure. For groups, it is possible to begin visit with an introduction of half an hour, either in the world of accelerators, or in the physics of particles (on request prerequisite to visites@sciencesaco.fr).