A definitively false UrbanMyth? of Cambridge is that it is possible to walk from TrinityCollege Cambridge to some college in Oxford (which one varies, but MertonCollege? is a favourite) without leaving the wine cellars of either. (PeterTaylor) That's even more extreme than the one I'd heard about it being possible to walk from Cambridge to London (usually, occasionally *xf*rd) on Trinity Land. This has another variant where it's possible to walk from Cambridge to London on StJohnsCollege's land.
Cambridge-Oxford on Trinity and Cambridge-London on Johns both *used* to be true. Not for some centuries now, sadly.