Creating location without Creation Kit?

[HivyGreys]

 

Is it possible to create dungeons, cities, etc. outside of the Creation kit? Maybe 3dsmx,blender or something else? 

[PeterMartyr]

no, but you will need 3dmax maya or blender to create unique nif artifacts and such. So it more like all the above

[scorrp10]

Sure you can create a piece of environment as a single .nif mesh file.    Prime example would be Halofarm Vignettes

 

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But you still need to make static world object form from that .nif, create a Skyrim interior space where that object will go, add entrance and exit markers, potentially furniture markers, light sources, etc.    All of that has to be done in CK.   If you want those spaces traversable by NPCs, you also need to NavMesh it.