The cache is not at the location above, but it is within 10
miles of it.
All you have to do is to work out from where the picture you see
below was taken.
Get yourself to where the photo was taken. No access or parking
from below! The picture was taken around 11am, if this helps. Stand
on the bridge, right over the middle of the central reservation,
and about 3 feet back from the rail. Take a waypoint in GRB36
datum, e.g SP xxxxx yyyyy. Then add 465 to the northing co-ordinate
and subtract 1003 from the easting. You now have the co-ordinates
of the cache, which is a 2L tupperware box with the usual
goodies.
Google Earth may be helpful if you are looking in the right
area.
Enjoy!