One of the major attractions to see in Osaka is the castle. This is actually a recreation (complete with lift) but looks pretty faithful to the historical pictures found within. My guidebook describes the castle as an inpenetrable fortress. Luckily for me you can buy tickets. This is the view as you approach:

This is the actually just the main tower. The rest of the castle consists of various walls and gates that are designed to confuse any attackers. A closer picture of the tower is here:

The grounds are nice with plenty of cherry blossom trees. Is it was Hanami there were lots of people camped out enjoying themselves. The thing to do in Osaka, apparently, is to have a barbecue.