Abstract
Gdansk in Poland and the Netherlands share a long-term relationship that started with the establishment of Dutch Mennonites in the Vistula delta in the 16 (th) Century. Climate-change figures show that both the Polish Gdansk and DutchRotterdam deltas will suffer flooding due to sea level rise, with accumulating severe rainfall accompanied by high river levels; reasons that led to a comparison of the adaptation measures taken. On the basis of the crossover comparison studied, it can be concluded that Poland and the Netherlands have a virtually identical approach when it comes to climate-change impacts on their current situation. With regard to the long-term climate-change trend, the Netherlands in exploring for the future more 'anticipatory' measures with the development of new scenarios for the protection of land and cities. In the Netherlands the use of Hackathon approach is thereby used more often to explore such scenarios. The interaction between the experts and stakeholders of different expertise in this methodology show to lead to creative and new perspectives. This approach may also be recommended for the situation in Gdansk.