Start by naming any country that France borders. Then name any country that borders any of those countries. Then keep going until there are no more countries left to name.
Based upon Wikipedia the stadium is not in Katowice, while it is very close geographically, I too will concur that i'll wait for a more educated opinion on it than mine!
It's just over 200m from the city limit of Katowice, I think it should definitely be accepted, since it obviously mainly serves the population of Katowice, being the largest city in the Metropolis GZM and Upper Silesian metro area.