Whether it be the ruined castles or celtic crosses, megalithic dolmens or round towers, Ireland's greatest treasures are made of stone. To my mind, they are at their most beautiful when you come upon them expectedly: unsign-posted, undeveloped. And yet we need them as part of our tourism. It's an old bone of contention now, but I would go for heritage centres away from these sites. I'd go for centres in local towns that highlight what's in the district, supply maps, information, lore.
If there must be development at the site, I'd go for small; not overwhelming. Carrowmore neolithic cemetery ( 6000 to 3000 BC) in Sligo is a case of the latter; the centre is modest, allowing the megalithic remains their space on the landscape.
St Patrick's Well at Oran, Co Roscommon would be passed in the blink of an eye as one drives around a bend on a road. The remains of the nearby round tower is the only evidence of its ancient importance. The unexpected discovery of the round tower added hugely to the pleasure of seeing the well.
St Patrick's Well at Oran, Co. Roscommon
Megalithic Tomb inside Cairn at Carrowmore, Sligo