Hay on Wye for sure, but do it at the end because you WILL buy books there! The best castle (for my money) is Carreg Cenin (between Llandeilo and Ammanford) as it's a castle of a native Welsh lord, and the best of his three in the mid-Tywi valley. It's not far from Llyn y Fan Fach with it's legends of the Lady from the Lake and her family, the Physicians of Myddfai. My other favourite bit is the stretch from St. David's to Cardigan - the cathedral is superb, Fishguard has a folk club, there are celtic crosses/ogam stones in Nanhyfer (Nevern) as well as the standing stones at Pentre Ifan and the recreated Celtic village at Castell Henllys, then the old church at Mwnt where you can also watch for seals and dolphins.

I'm sorry I can't offer a place to rest your head in June or July as I've got either a full house or no plumbing!

Sian