The brick walls were supporting the huge earth banks piled around the building, making it one of the most protected on the site.

This was also one of the nastiest areas of the site. A local farmer uses Upwood to graze his sheep – and this area of the site is where the sheep go to die. There were several sheep carcasses in various stages of decomposition here.

One mystery remained. This was a fairly small Gas Decontamination Building – the undressing and bleaching rooms were one room for instance. And they were normally partitioned in two – each side for male or female personnel. Why did it seem that Upwood only had half a decontamination building?