If one big wall won't do, several low walls with level terraces between may be the right solution. Consider paving a level to create a patio and a comfy seating area. An inviting midslope patio is a great place to sit and survey the rest of your garden.
Potato Pot: The most environmentally friendly potatoes are grown this way. in Japan ! Make a potato pot by cutting out the sides of a plant pot and putting it inside another one - this makes it easier to lift the plants out for harvesting.