Nagoya's Castle is much larger than the one in Okazaki, and much more photogenic. It seems similar in size to Matsumoto Castle in Nagano (see the Asia update from 2001 for a photo and description).
They have turned the inside of Nagoya Castle into a museum, complete with artifacts from the original castle (most Japanese castles have been destroyed over the years, so the ones you see are reproductions). The artifacts were definitely interesting (and worthy of photos, but unfortunately they don't allow pictures to be taken inside the castle). But I think I appreciated the life of a lord and the soldiers more when I saw Matsumoto, whose interior was more set up as the castle originally was (low ceilings, steep stairs, and all). If you had to see one, that would probably be my choice (but better yet to see both, as they show different things).
The stones in the foreground of the picture above are ruins from one of the original buildings. It was an all-wood structure (except for the base stones you see) which they have plans to restore in the near future.
I find the corner stones used for all the rock work on the walls to be very interesting. It was ingenious to build in this fashion - locking the rocks into place and supporting the weight of the structure above. And still plenty formidable as a defensive structure.
I also bought an interesting 'only in Japan' contraption. It is a small beer keg system, complete with CO2 cartridge to keep your 'keg' pressurized (and the beer fresh). Downside is that you have to buy Kirin beer (not my first choice of Japanese beers) and it only comes in the 1.5 liter size. But I still had to try it out. Gives a bit of head for the first beer (like a regular keg), but then works just fine after that. Even came with a little drip tray...
