If you come to Duluth you really must go to the park at the end of Park Point. Many sand volleyball courts, space for soccer, softball, flying kites, running, picnicing, grilling. But the gem is the lake and the wonderful 5 mile long fine sand beach. Beach comb, play in the "refreshing" waves, sunbath--just chill without any crowds to deal with. You can find plenty of place to stretch out. Make an afternoon of it. And if you like hiking, go to the very end of the road, walk past the small local airport and into the old growth forest--another few miles to the next canal used by lakers coming in and out of St. Louis Bay but without the crowds of Park Point. All free.