Sparks Marina Park is pretty big, peaceful, beautiful, and mostly well kept (except for the unfortunately inevitable bird droppings) It does get somewhat crowded with people at times, but it's usually not bad (and generally the people there are nice). It's a pleasant place to walk, there are some benches and tables, and an enclosed dog park. I've never needed to use the restrooms there so i'm sorry i haven't any comment on their condition.