I've done a fair few of the sites round Ilkley Moor, but
never been over to the Grubstones...
there's a picture of them here:
http://www.arch.wyjs.org.uk/advsrv/RomanWeb/rw52.html
The site doesn't look too hot really! It's probably
better to head in the other direction, where all the rock
art action is! :-)