The walls are going up. Unfortunately the wall obscures a feature which is indicated by the rods which can just be seen over the wall to the right of the doorway. I asked that the pillar that supports the telescope be detached from the floor as I didn't want any chance that vibration in the floor would transmit to the pillar. When I realised that the floor was concrete several inches thick supported on blocks on concrete foundations thick enough to support a house, I wondered why. However the builder put a square of insulation block in the centre before casting the floor and these rods will enable it to be pulled out. He will then dig down to give me a solid foundation to the pillar. I just hope it works.
The wall on the right of the picture is part of the landscaping of the garden.