"Where do we want to go?"
Translation:Nereye gitmek istiyoruz?
The -ye suffix is because of the dative case, which shows movement to something. The -de suffix is because of the locative case, which shows location. Whenever you are saying where a static object is, you use "nerede," but if you're asking where an object is moving to, you use "nereye."
Hope that clears it up! :D