Underneath the western "arch".
Centre photo is the lintel beam that spans the gap between the two western
pillars and still supports part of the roof. The tops of the pillars can just
been seen
on either side with the wall-embedded slabs above them. Top of photo the
parallel lintels of the entrance passage continue into the chamber and end at
the main lintel beam. The grey painted stone and concrete bottom photo is all
modern.
North is upper left corner.