When running at large can get your owner a big, fat ticket, but there's no place in the city to blow off some steam, what's a pooch to do? That was the quandary facing the Aurora Parks Department, and last year they finally did something about it. The Off-Leash Dog Park -- basically a five-acre fenced-in field of mown native grass next to the water -- gives canines a place to run and chase things, including each other, without the encumbrance of any sort of restraint. They are free to play Frisbee, sniff and be sniffed, and run wild -- so long as humans clean up after them and keep some semblance of order.