Blair said he couldn't see a way into it from the north either - and certainly on your map I can't identify the paved pathway around the northern end of the building, but on my map it's legible although narrow.
Exaggeration, a much under-rated aspect of sprint terrain mapping. It comes from a too strong desire to adhere to the underlying aerial photo.
Good point Neil. Also a good example of why ISSOM has minimum widths for areas.
I also did not see the route on the north end of the building until I got my map back
Neither did I (and, like many others, I read closely-drawn stairs as impassable barriers in a couple of spots). However, having seen a control on a bridge coming into 12, I was ready for 13 to be similar (which it was).