St Catharine's College is one of Cambridge's older colleges, founded in 1473 and tucked close to King's Parade. Its courts are more intimate than the showpiece colleges nearby, with a handsome mix of late medieval foundation and later rebuilding.
Access depends on college rules and events, so treat it as a college to look for while walking the central cluster rather than a guaranteed interior visit. When open, it gives a calmer counterpoint to King's and Trinity.