Reuters/Thomas PeterTokyo's Tsukiji market just might be world's most famous fish market. It's certainly the world's busiest, as around 2,000 tons of fish change hands here daily. It's worth a trip simply to see enormous fish thrown around like footballs, as well as the famous 5am tuna trade. Afterwards, grab a bite to eat at the onsite market, which has hundreds of food stalls and restaurants. For a sushi-for-breakfast adventure, visit Sushi Dai, which is right near the market and thus serves some of the freshest rolls in town. Or, you could head to Sukiyabashi Jiro, the three Michelin-starred sushi joint of Jiro Dreams of Sushi fame, said to be one of the best sushi restaurants in the world.