In the summer of 2023, cinema audiences flocked to the movie Oppenheimer, the epic telling of J. Robert Oppenheimer’s role in the US Manhattan project that encompassed so many brilliant minds, including a host of European physicists in exile. Perhaps there is a sequel in the works, recounting the further exploits of those Manhattan-project physicists as they drove exciting progress in fundamental physics? Or maybe the camera could focus on post-war Europe, bombed out and exhausted — but mobilizing to build new relationships between its nations and to forge the scale of collaboration that would restore its capabilities in nuclear research on the world stage.

In those post-war years, several famous names, Niels Bohr included, mooted the idea of a European centre for nuclear physics. In 1949, Louis de Broglie proposed to the European Cultural Conference that a central laboratory be established; then Isidor Rabi pushed the newly minted United Nations Educational, Scientific and Cultural Organization (UNESCO) to “assist and encourage the formation of regional research laboratories in order to increase international scientific collaboration”. In 1951, UNESCO resolved to create the European Council for Nuclear Research (whose acronym in French is CERN), and within months 11 European nations had signed up. The city of Geneva, geographically at the centre of western Europe and in neutral Switzerland, was chosen as the site of CERN’s laboratory, and construction began in 1954.

It was on 29 September 1954 that the convention establishing the European Organization for Nuclear Research — perennially known as ‘CERN’ — was ratified by 12 European member states. In the 70 years since, membership has grown to 23 member states, with associate members including Brazil and India, and Japan and the USA as observers. What began as a European project, in competition with other facilities around the world, has become a shared global enterprise.

The large experimental groups at CERN have long been known as ‘collaborations’ — and that’s exactly what they are, successful international collaborations built through the efforts of generations of physicists, engineers and technicians. Over the past 70 years, those collaborations have produced numerous scientific breakthroughs. In this Issue, seven members of the new generation of CERN physicists tell A history of CERN in seven physics milestones — from the earliest accelerator, built in the 1950s, to the discovery of the Higgs boson in 2012. And 70 years at the high-energy frontier with the CERN accelerator complex looks at the history of CERN’s accelerators, particularly the showpiece 27-km tunnel that has so far housed two frontier-busting machines — and might host more.

As befits its origins with UNESCO, CERN has also been a champion of education, through its outreach activity and an active programme of site visits for schools and the public, and of the cultural connections between science and the arts — something Nature Reviews Physics explored in a series of Q&A articles earlier this year1,2,3. Throw in the invention of the World Wide Web, and CERN clearly has 70 years of broad and valuable contributions, to science and society, behind it. What of the future?

CERN’s flagship machine, the Large Hadron Collider, will shortly pause for an upgrade but is then scheduled to run into the 2040s. Currently the particle-physics community around CERN is in deep discussion of the options for future colliders, as part of the latest update to the European Strategy for Particle Physics which will be published in 2026. The strategy is closely coordinated with the particle-physics programmes of the USA and Japan, reflecting the fact that the field has become increasingly centred on very few, very large-scale experimental facilities. Indeed, one possibility — a CERN-based Future Circular Collider — is extremely large, requiring a new 90-km accelerator tunnel to deliver a physics programme through the 2070s and beyond. It is an epic undertaking, and some question whether the present community should tie future generations to this mammoth project. The recommendations of the European strategy update are thus eagerly awaited: they must provide a clear way forward, achieve broad community support, and secure a future for international collaborative endeavour. Just as CERN has done for the past 70 years.