There are a multitude of reasons why one should visit the coastal city of Viana do Castelo.  The views from atop Mt. Santa Luzia are breathtakingly beautiful.  The historic city center is charming and a visit to Igreja de la Misericordia is well-worth the price of a train ticket.  But, when you get right down to it, the reason everyone should visit Viana do Castelo is to eat doughnuts.  Yes, you heard me.  The city is famous for the Bola de Berlim.