Despite the late hour and the shuttered shopfronts, the square was alive and pumping. Diners mulled over their meals while children raced around an elaborate fountain, turning a deaf ear to their parents as they ran through the frigid spray. Couples sat entwined under trees as more gregarious groups of friends spread out over park benches. All conversations were centred around the communal mate, as friends shared their gourd around, topping up from steaming thermoses of hot water. We followed the thumping beats of live music to find a group of octogenarians, their faces sallow under the street lamps, but expressions vivid, demurely doing the tango. It was tango danced like I’d never seen before. Groups of onlookers cheered and some even joined in. And in that instant, I was utterly captivated.