I decided this evening to get out into the (cooling, but still quite hot!) air and cycle to Witney for a pizza picnic. And if I was going to do that, I figured, then it’s not much of a diversion of my route from Stanton Harcourt to go via the first half of the Tar Lakes/South Leigh Loop while I’m out.
I started by cycling up the old West Oxfordshire Cycleway/Tar Lane to this car park. I’ve walked around the lakes previously and noticed the position of the object referenced in the hint, and so as soon as I was in the vicinity I knew where I’d be looking. Soon the cache was in hand!