I have visited and had lectures at the UK’s national synchrotron science facility, known as the Diamond Light Source (or ‘Diamond’ for short) in Oxford.
Diamond works kind of like the Large Hadron Collider, in that its a big (though not LHC big!) loop that accelerates particles. Synchrotrons don’t collide particles like the LHC, they are used to make incredibly intense radiation which is funnelled off for experiments that are run around the edge of the ring.
Its an amazing place, with some really interesting people. I visited for a few days, and learnt a lot while I was there!