The southern pillar.
Both the southern and eastern pillars are quite a bit shorter than the northern
pillar so there is a large number of "eke" stones inserted above and below the
slab
the protrudes from the walling. Perhaps because of this precarious arrangement,
two further slabs embedded in the walling meet above the first at oblique angles
providing added lateral stabilisation. This arrangement is mirrored above the
northern pillar, but not the other two.