Grass pathway through the vegetable or flower garden and a twig arch on each end of the path. Remember to make it the same width as the mower. The twig arch would look great with a gate. Image from the Complete Kitchen Garden Book
Possibly in the corner of the back garden? Like the beehive baskets, the tepees for vines to travel, the raised beds and the different enclosures for the vegetables, the soft grassy path -- what's not to like in this awesome garden.