This place is getting even more special, I've found an identical vitrified fort called Barra Hill in Perth - 0.2 Hectares, same interior shape - no entrance!

The vitrified paper is coming along great, It's about twelve pages long and I've got five example sites. still need more.

I've got another reason for these forts, applicable to Craig Phadrig and Barra Hill. They were the place for the tribal party, every year, or more often they'd pile em with brash and wood and make a great bonfire, then in the heat of the fire they'd dance nude with the fairies. The regular heating could melt the stone over time.

No that does not work, the heat has to be sustained in order to penetrate and 'cook' the stone.

Here's another, a tribe, suffered a great loss at the fort, after they had vanquished their rivals they held a bonfire of mourning, which burned one day for every life lost. The small size of the hill forts in the case of Barra and Craig Phadrig may indicate the fort was symbolic, built for the occasion.