Its years as a working-class neighborhood allowed San Telmo, considered Buenos Aires’s oldest neighborhood, to avoid development and conserve its low-rise, historical architecture. Today it’s no surprise that the area has become the go-to spot for antiques. There’s a large cluster of shops surrounding Plaza Dorrego and on Defensa Street, plus an extremely popular—and all but impassable—flea market on Sundays. If you treasure the printed volume somewhat more than creepy dolls and tarnished silver, head to Walrus Books, one of the city’s few English-language purveyors, which is stocked with a beguiling collection of secondhand books. The mix of Latin American literature in translation alongside Anglo-American classics guarantees you’ll find a great title for the long flight home.