I think there's a case to treat the grounds of Medway Crematorium like a cemetery. Each of the glades on the property is well defined (see plan) and each presumably contains the cremains of hundreds (thousands?) of people. There are also facilities for visiting one's deceased relatives.
To me, the category "Cremated. Ashes scattered" is for when the relatives take the ashes off site and scatter them at a location significant to the deceased.