The first third of the entrance passage.
The passage has narrowed and dropped in height considerably at this point. The "blocking" slab found by Burroughs can be seen lower centre.
This slab is 0.2m high and 0.3m deep, it spans the entire width of the passage floor, its ends are bonded into the masonry of the sidewalls, so it is
definitely an original feature of the cairn structure. Although referred to as a "blocking" slab it is obviously not large enough to fulfil this function and
must have some other purpose. Similarly, the long external extension to the passage is often compared to a drain, but the location of this fixed slab
would not allow the flow of fluids along the passage.