Right around the corner we have a MASSIVE dog park with tons Trails and a large open field. I take Kentucky every evening for about 2 hours. He runs around with every breed of dog possible and just loves it. He is off leash the whole time - mainly trying to catch squirrels or little dogs that resemble squirrels.
Here is his new favorite activity after rainy days. Not only does he walk through EVERY MUD puddle but he likes to take a bath in them, rolls around, dunks his head, herd every other dog in with him.