Old town is one of my favorite places in San Diego, and is one of the few must see places in San Diego. There's the historic aspect of things. They still have the original houses (the houses all have the names of the original inhabitants), a school, court house, various stores. Of course, some of the houses have turned into souvenir shops too. They have a visitor center that shows the layout of the original San Diego that's worth a visit. On top of the historic sites, there are many good restaurants in the vicinity, mostly Mexican food. Perfect place to go and have fun and have some good food.