My outdoor cubby

I love this space in my yard. It is ALWAYS in the shade so it isn't ever going to be a garden spot but it feels like it has such potential It is much deeper than it looks here. From the left edge of the arbor vitae to the other side on the right is about 20 feet and it is 12 feet deep. It wants a sitting area there. Not really a picnic area as it is just off the street and the deck works well for that but something that isn't going to get carried off by the wind (or less honest neighbors) The ground is mossy and our colder/drier than usual winter has been hard on it, but if we get good spring rains this corner stays green and lovely. Anything here should be permanent but I don't mind moving cushions. Any Ideas?