After Plaza de Mayo, Plaza Dorrego is the city’s oldest plaza. Dating back to the 18th century, it was originally a pit stop for caravans bringing supplies into the city from the Pampas. Now a lively square surrounded by colonial buildings and old-world cafe-bars, it's popular with tourists who come to watch tango dancers and musicians perform (get ready with your spare change when they pass the hat around). It's also the heart of San Telmo’s famous Sunday street market.