At NAVAN the River Blackwater meets the Boyne. It’s an historic crossroads – important in the days when the waterways were the chief means of transport – and also a modern one. The N3 comes up from Dublin to follow the course of the Blackwater to Kells and to the Loughcrew Mountains in the northwestern corner of Meath; the N51 arrives from Drogheda to continue into Westmeath, its interest diminishing rapidly as you go; and to the south you can take the N3 to Tara , Dunsany and then go eastwards on minor roads to Bective Abbey and Trim.