Put an outdoor kitchen where that brick wall is with a fireplace and have a gate into the larger part of the back yard. Pergola connected to house and fence, over dining area in courtyard. fantastic design for narrow patio - James Farmer
A big sauna with a huge window looking out on the forest and the outdoor hot tub that's big enough for many people to warm up from the cold. This could also be used as a cold pool for dunking after sweating in the sauna.