Where on Earth is... Llanigon?

I mentioned Llanigon previously, and then realised that only people with a good map would be able to find out where it is.
Llanigon is the next village along towards Brecon. It's possible to walk it - I used to live in a longhouse above Llanigon (past the sign saying "Lost - This Way"), and I used to walk down from there. It was more pleasant to cycle, though, apart from the steep hill at the home end of the journey.
Llanigon has a primary school, a community hall, a church, and the Old Forge Garage, which also hires out vans. Once upon a time, it had a Post Office, now the Old Post Office B&B, which does rather good vegetarian food.
And that's it - no shop, no pub.
St Eigon's Church is, I think, the only church in Wales with that saint's name, and it's a wonderfully ambiguous name. According to which legend you believe, Eigon could have been the daughter of Caractacus, who went with him to Rome when he was captured by the Romans. There she met St Paul, who taught her Christianity personally, and when she returned to Wales, she set up the very first Christian church in these islands. In support of this story, there is an Iron Age hill fort in Llanigon, at Plas Celyn Farm, which is reputed to be one of the places where Caractacus lived.
The other (more mundane) option is that Eigon was male, and a monk who followed St David. When St David sent out missionaries throughout Wales, Eigon ended up here, and built his church.
Sadly, with all this legendary controversy, the church building itself is quite boring, though the yellow altarcloth is made of the very same material that was used for Rowan Williams' cope when he became Archbishop of Canterbury.
When the Hay Festival site was moved further out from the centre of Hay to its present position, there were local mutterings that they may as well call it the Llanigon Festival now.