There is a saying in Argentina that reflects its people’s European roots: “Mexicans descended from Aztecs, Peruvians descended from Incas, and Argentines descended from boats.” Indeed, the country’s saga of immigration rivals that of the U.S. Many Argentines, like my wife, have made a second migration of sorts to America; nevertheless, her Basque and Italian heritage is as strong in Washington as it was in Buenos Aires. But you don’t have to be Argentine to enjoy Argentina National Day‘s celebration in honor of the country’s independence from Spain: Anyone who loves empanadas and tango should find both aplenty, with such performers as Grupo Folklórico Argentino, Pampa Salvaje, Eva Rey, and dancers Jorge and Monica. From 12:30-6 p.m. at Barcroft Park, Four Mile Run Dr., between George Washington Dr. & S. Walter Reed Dr., Arlington. FREE. (703) 358-6416. (ED)