Trying to identify photo location

Bit of a long shot, this! I'm trying to identify a location in
Picardy.
http://www.terrypin.dial.pipex.com/Images/19990811-Eclipse.jpg
That was taken looking roughly east at about 11:30 GMT on 11th August
1999.

Apart from the vanishingly small chance that someone here recognises
the area, I'm hoping maybe for another suggested line of enquiry
please.

I traveled with my wife to France for the Eclipse. We took an early
morning ferry to Calais and drove fast south down a motorway to ...
Location Unknown! We left the motorway and parked in a lane a short
distance away, almost certainly to the east of the motorway. We had a
picnic lunch with a bottle of wine, observed the eclipse, dozed for a
while, then went to a small town nearby for coffee. Then we drove back
to Calais to catch the ferry.

After staring at road maps for a long time all we can say is that it
was somewhere south of Abbeville. I'm not even sure whether after
Abbeville we went towards Amiens or Neufchâtel-en-Bray!

If the location was the UK, there would be a chance that someone in
the uk.rec.walking newsgroup might recognise the area. But I cannot
find any equivalent French group. No 'fr.rec.randonnée' for example.
Yesterday I also tried fr.rec.voyages, fr.rec.sport.divers, and
fr.rec.photo, but no solution so far. Also just posted OT to
fr.rec.montagne. I hate unsolved puzzles and I'm determined to get
this photo accurately captioned!

--
Terry, East Grinstead, UK