Central Osaka is often divided into two areas referred to as Kita and Minami. Kita is roughly the area surrounding the business and retail district of Umeda. Minami is home to shopping districts.
Osaka's best known sight is the Osaka Castle. Think of it as a museum built in the shape of a castle, rather than as an actual historical castle. Still, it's pretty enough from the outside, especially in the cherry blossom season when Osakans flock to the castle park to picnic and make merry.