The little shops are great. There's a lot of bar scenes at night, but it's pretty quiet during the day with regard to that scene.
We took an ATV tour and that was decent, took us to a waterfall, and we got to drive through the city.
La Leche was a cool restaurant, we enjoyed that. And pretty inexpensive, relatively speaking.
Go south on the main highway out of the city and you'll find little towns and beach areas to enjoy. We did a couple of hikes there and had a great time.
Enjoy!