The floor in the centre of the lower
The floor of the lower chamber and first third of the passage is said to be bedrock (6), but the seams visible here look very much like slabs, especially
in the area around the entrance passage (right). It may be that what we see here are the marks left in the bedrock after slab quarrying.
The central vertical slab set into the north wall can just be seen lower left with a stone bench slab on either side.