Sometimes we never know what are on top of roofs.
Up to now, we still don’t quite know what they are.
The cylindrical golden thing on top of the roof is definitely not a water tank.
It is also surprising to see there is a skull like thing on top as well.
We can only surmise that they are related to religion / folklores in Inner Mongolia.
There is symmetry on both sides of the main structure. These objects are repeated on the other side.