There are several obvious depressions in the cairn, perhaps indicating where individual burials were made. There has never been a thorough investigation at Dun Bharpa, but the cairn is so impressive that you have to wonder what archaeologists might find if they did excavate the site!
I know what I found; wind so strong that it literally knocked me over. Strangely, I didn't have a wind gauge with me, but consider how strong it would have to be to push a reasonable fit full-grown man off his feet. I supposed you could say that I was completely bowled over by Dun Bharpa!
The easiest way to access Dun Bharpa is to follow the Craigston road to the parking lot at the end, then follow the obvious farm track deeper up the valley until you come to the ruined blackhouse at the end of the track.
Turn uphill, keeping the farm fence on your left, and carry on for about 10 minutes until the dun will come into view in a gap of the hills above you. Wear good waterproof footwear as the going is boggy in places.