The real fun in Rio de Janeiro will begin Saturday, when fans get their first taste of medal events at the 2016 Olympic Games.
Safety concerns immediately enter the forefront, when open-water swimmers compete in Rio's polluted water.
Before Michael Phelps attempts to claim more Olympic gold, fans will get their first look at Katie Ledecky, a 19-year-old swimming star poised to bolster the United States' medal tally.
Four years ago, the U.S. led the London Games leaderboard with 103 medals, including 46 golds. As of Saturday morning, every nation stands on equal footing.