Visited 9th November 2002: Croes Faen is very easy to find, and you can get good views of it from the road. The stone is exceptionally tall and slender, with two vertical edges on the south east side of it.
Croes Faen is almost certainly not prehistoric. It's thought to be the remains of a Medieval cross, the head having been removed or knocked off at some point. Croes Faen means stone cross.
According to Frances Lynch the exact origin of this stone is unknown - it hasn't been excavated. It may well be a prehistoric marker but it could very well be a Christian stone, like the one (7th-9th Century CE) found in the nearby church SH588009 or it may just be a rubbing stone for the cattle!