I would so much love to see you approach Muntermellan :-) It is a dog's arse of a site to get to! You'll love it when you get there though.

For Gortnavern park at the top of the slope before the ruined cottages - you'll know where I mean - and walk the rest od the way up the track. When you reach a barbed wire fence climb over it and carry on walking along the fence for around 150m or so. Last time I was there the farmer told me he'd clear the gorse from around the tomb. If he has done so you will see it easily. If not you'll need to keep looking left until you see an easy path through the gorse. The tomb is just through that. Enjoy :-)