A nacelle shell structure which is attachable to a main structure of a wind turbine is described. The nacelle shell structure is attachable to the main structure such that the nacelle shell structure is carried by the main structure at only three static points. Moreover, a nacelle shell structure is provided which is attachable to a main structure of a wind turbine. The nacelle shell structure includes interconnected shell sub-structures. Furthermore, a lock-labyrinth for positioning between a rotating part with a rotation axis and stationary part of a wind turbine is disclosed, which includes a shield structure and a support structure, the shield structure being located radially outward of the support structure and protruding the support structure in axial direction. The shield structure includes a nose protruding radially inward and being located at an axial position where the support structure forms a water-tight channel which opens towards the nose.