Shinjuku is one of the largest areas of Tokyo, its so freakin large it is pretty much a huge city itself. Not only is it a huge business district, it is also one of the largest and most popular entertainment districts in Tokyo. You could literally spend all day checking out each of the stores over here as well as the arcades and pachinko parlours (if that sort of stuff floats your boat). Various events also happen here, during one visit I just happened to stumble across a free music festival in full swing on the street. Shinjuku can get incredibly crowded over the weekend, so I would avoid visiting then if you hate the crowd. Also, the station happens to be one of the busiest in the world, it is so big that I actually got lost in the station the first time I went there! I actually don’t like Shinjuku very much, naturally being one of the biggest entertainment districts it is quite dirty and sometimes the streets can also stink. Also Shinjuku is home to the infamous red light district Kabukicho, I really wouldn’t recommend visiting this place, especially at night as it can be dangerous (I have also heard that the yakuza hang out a lot late at night around Shinjuku). On a rather random note Jackie Chan was actually spotted drinking in Kabukicho recently, apparently his new film is going to be set there and he was doing some rather enthusiastic ‘research’ for it!… Anyway, love it or hate it Shinjuku is undoubtedly one of the most popular tourist hot spots in Tokyo.