The interesting thing about this building is that it has no central pillars in its foundations, and a construction that is normally used to build roofs as the basis for the 'real' tower.
And here's the complete tower:
This picture shows a part of the creative lowest layer for the read, upper part of the tower. It is a layer built from small, long stones set along the diagonals of the tower's cross section (they look a bit like wooden beams coming out of the building) with triangluar pieces between them to produce an even bottom for the rest of the tower.
And here's the complete tower as the birds see it: