The Tsukiji Fish Market is one of the most famous attractions in Tokyo, housing the largest and busiest fish market in the world. While one typically has to get up crazy early (like 4am) to make it into the actual market and see the tuna auctions, we took it easy and arrived late, walked about the outside areas, then had lunch at the famous Sushi Dai.

http://www.japan-guide.com/e/e3021.html