A Guarda sits at the very southwestern corner of Galicia, where the river Miño meets the Atlantic and the Portuguese border begins. It's a working fishing town, famous in Spain for its lobster (the Festa da Lagosta is held every July), with a small but lively harbour and a string of seafood restaurants along the quayside.
The reason most visitors come is the Castro de Santa Trega, a Celtic hill-fort excavated on the steep hill that rises behind the town. The foundations of more than a hundred round stone houses are visible, and the views from the summit stretch over the Miño estuary into northern Portugal — worth the steep climb on a clear day.