We analyse the impact of the establishment of the Diamond Light Source synchrotron, a large basic scientific research facility in the UK, on the geographic distribution of related research. To account for the potentially endogenous location choice of the synchrotron, we rely on the availability of a ‘runner-up’ site. We use data on academic publications to trace the geographic distribution of related scientific inputs and outputs. Our results suggest that proximity to Diamond had a positive impact on the output of related research. This proximity effect appears to be driven by an increase in inputs rather than the productivity of scientists.