It was an unseasonably warm autumn day with the temp around 16c (61f) rather than the average for this time of year of about 12c (54f).
For those who don't know, Offa's Dyke was a ditch/earth mound that was built by King Offa of the ancient English kingdom of Mercia. It was built around about 785 AD and was designed to keep the marauding Welsh out of Offa's kingdom.
Apparently it was originally about 90 ft wide and about 25 ft deep/high and used to stretch about a couple of hundred miles long but now only something like eighty miles of it is left. As you can see from my photo what's left is little more than a grass mound but in some areas it's a bit more impressive.