This splendid park is the place to hike when you sleep till noon on a Sunday, go out for waffles and read the paper, and then decide you'd like to get away from it all for a while before it's dark outside and your office is making its usual Monday morning claim on your life. Sloping from pine tree prairies down to the rolling St. Croix River, Afton offers something that's in short supply around these parts: topographical variety. God bless the plains, but strolling along three miles of level turf is a little like completing three laps around the third floor of the megamall. Once you get off the paved path along the sandy St. Croix riverbank, a variety of trails winds off to the north and west. These lead you past a few hike-in camping spots and up to a quiet meadow that overlooks the ski lift across the way. Even the ornithologically challenged can't help but spot the meadowlarks in these rolling grasslands, perched in hardscrabble trees above the prairie flowers. Tromping up and down these hills on a summer day, you may build up enough sweat to require a stop at one of the beaches along the river. How about dropping the state plan to construct new ballparks and building some more mountains instead?