Image Owner:
munki @ Shootability.co.uk [concept and or portions of image]
Having oriented and scaled the image of the 1620's map and with the help of the more understandable 1840's map it is possible to overlay more modern maps of the area to get a pretty good idea of the location in today's landscape.
This solution could be fairly inaccurate on the ground but I think we can be pretty sure within the grassy area. This area has also been known as the 'Robbers Patch', another local legend and site of the old gallows tree. More of this later...
It looks as though Rivington Lane (which is a fairly modern construct from the estate of Lord Leverhulme) passes directly over the site. Returning to the aerial photo from the top of the image I fancy it is possible to see the narrow path of the old race course as a shallow ditch below the trees in the top right, leading towards the centre of the grassy area where there appears to be a broader and more defined dip in the ground. It seems this could be the actual site of the old Plague Pit. Spare a thought for the potentially hundreds of corpses, hurriedly buried in a mass grave during one of English history's greatest tragedies.