Cosmo Tower Observatory
Most of what I saw in Osaka during the night time and day time all happened within two days. Most of the touristy destinations in Osaka were located in a pretty central area, so you didn't need to spend too much time around the city to hit most of the recommended tourist destinations.
Cosmo Tower was my last destination for the day. It wasn't too far away from the main city but it was still a good 15-20 minutes by subway. There wasn't very much to do around this area except for the observatory and the aquarium. There was the Universal Studios theme park around here as well, but it was located on the harbor across the one that I was on so you had to ride a different subway line.
Cosmo Tower had a wonderful observatory and it had an amazing view of the harbor area of Osaka. If I were to compare the views between here and the observatories located in the cities, the observatory here had a much or open and refreshing view that had a sense of zen. The view from the cities had a sense of energy, vibrancy and a sense of tightness.