Cambridge and its approximate surroundings now have 5 out of the 6 native owl species in the UK. The only species it lacks for obvious reasons is the eagle-owl.
Tawny owls breed and reside in the city center, most notable Jesus college. I have personally seen the young roaming the college grounds towards the evening, and 2020 was a hugely succesfull year for them, the pair managing to raise four chicks which later dispersed and were heard in a variety of locations.
Little owls can be reliably seen near Waterbeach station. I was down there recently and can confirm they still use the area and are remarkably easy to see in the evening...if you know where to look, of course!
Barn owls, most notably, are present in the south of Cambridge and also at Landbeach, where more than two pairs have been seen
Short-eared owls are all over the place in the winter. Traditionally they preferred Burwell Fen however they are now favouring Great Fen instead
The only long-eared owl roost I can reveal without risking disturbance of the birds is at Deeping Lakes near Peterborough just over the border in Lincolnshire. The birds roost on an inaccessible island and even then are remarkably difficult to see, even if you know where to look.