More than just a lake, Rio's Lagoa serves as a sports venue, fishing hub, exercise route and important geographical point around which the city sprawls. Plus it is breathtakingly beautiful. Surrounded by mountains and circled by some of the most expensive real estate you will find outside of Leblon, every December the traffic grinds to a halt as locals and tourists pack the banks to see the traditional floating Christmas tree light show. The rest of the year you are as likely to see wakeboarders as sailors cutting through its waters, while at various intervals dotted around the edge are some wonderful open air bars and restaurants. At 7.5km in circumference it makes for a healthy run or cycle, but is also at its best taken in at a leisurely stroll at sunset before a well earned caipirinha.