Not a stone monument, but there's what looks like could be a hillfort type affair at TQ751650, quite close to Horsted Way. Could that be what you're thinking of?

Comes up quite well on Google Earth, but I haven't worked out how to give a link to that yet (can anyone advise?)

Might be this:

http://www.pastscape.org/hob.asp?hob_no=416475&source=textonly&period1=None&county1

Cheers guys, looking forward to hearing what you find.....

I had a scout about up on Blue Bell Hill a couple of years ago, there are a couple of interesting looking stones thats for sure. Found what could have been an 3 stone tomb entrance on the other side of the a road above the white horse stone at TQ759608. Its a stile but it made me stop and stare for a long time.

The farm next to the field with the coffin stone in has a spring in its yard / garden, with an interesting stone setting about it. Suposedly another setting existed up at cossington.