I'm from Kraków so i say 'I'm going na pole'. All my Polish friends from different parts of PL say ' na dwór'. And they make fun of me ;) lol.....
How do you say it? :D
It is quite easy to guess the origin of this difference. In the past , Krakow residents used to live in nice houses and residences, so when they left them they said they were going "na pole," (to the field). The field was sort of a recreation area for them.
All other Poles, in Warsaw and elsewhere, used to live in crumbling cottages, so when they left them, they said they were going "na dwór" (to the mansion). It was their favourite entertainment to look at the mansion and watch people there. Like at the cinema.
That`s what some guy explained to me once.