Real Estate / Can a German Citizen buy a piece of Land to build house in Poland? [14]

I am German citizen (leaving in Duesseldorf) with intension of buying a piece of Land(2000sq.meter) in Poland area of Podlaskie and build house there because i have a Polish girl-friend and two children there leaving.Is foreigner allows to buy a land and build houses?I love my children to grow up in this area than in Germany. I am every 2 months with my family in Podlaskie,Poland