Solved Some places on the farm where I can't build anything

[tornadojack]

There are some places where I can't build anything.
In front of cave entrance - that's understandable.
But what is the reason for place on the picture?

 

[Geoman265]

The place on the path above the statue is reserved for a spouse. The spouse will have a special area there. The area in front of the statue may have a similar reason, so that the spouse can still walk there.

 

[Odin]

As Geoman mentioned, those spots are intentionally reserved.