Our garden is quite small, but we've a fair bit of space at the side that took us 20 years to work out what we needed to do with it, that's when we decked it and put the summer house on about 4 years ago, with two large raised beds (I built it as part of my broken spine recovery). It had been for growing veg, but we were too busy with work.
The back garden is tiny, but does have a conservatory, hot tub, arbour, cat run and a blooming trampoline in (not on photo's but to right of the arbour/cat run shot.
The cat's access the cat run via a side window in the conservatory, then have access down to the arbour, under that, and you'll see a mesh tunnel just above the curved fence that runs along the back to two 'viewing platforms', one near the garage, the other behind the arbour.
We've also got a raised deck to the right of the hot tub, which fills in the waste space behind the garage - it's nice to sit on on a sunny evening, as there is just a field behind us - that was built during shoulder surgery - one handed !!
The hot tub was moved to the permanent 'gazebo' a couple of years ago. It's glazed both sides to allow the light through and the roof is perspex. We leave the tub up all year round as the first year we tried to store it, and that's when you get 'punctures' as the plastic is very tough and doesn't like being folded when 'cold'.
My back garden grass is looking fab at the moment - it's been fed with iron sulphate diluted in a watering can. Great stuff and a fraction of the cost of "lawn feed". The other lawns are picking up now with some much needed rain - the back garden has much better soil as we put that down, rather than the builders (the front and side are very dry).