I went back during my lunch hour today, without my GPS receiver, but with the hints. Found it easily this time!
I heard, then saw, woodpeckers pecking at the trees, searching for bugs. Then I ate my lunch at the Eagle's Nest, overlooking the spectacular Wye Valley.
Took a book about birds; left a squirrel.
Smaug also hopped into the box before I closed it. He is starting the next leg of his journey home.