Nothing will ever knock açaí off its perch as Rio's street corner cool-off of choice, but frozen yoghurt is slowly catching up. Lured in by the promise of fat-free tasty treats and an ever-changing list of combinations from coconut to graviola and even, sensibly, açaí, cariocas have been woo'd by the cups of cold creaminess. Opt for a variety of toppings with which to tip the balance firmly away from 'healthy' and more towards 'sundae', including M&Ms, nuts and chocolate sauce, but the tinned lychees are a refreshing delight.