Problem
In many places, walls and fences between outdoor spaces are too high; but no boundary at all does injustice to the subtlety of the divisions between the spaces.
Solution
Surround any natural outdoor area, and make minor boundaries between outdoor areas with low walls, about 16 inches high, and wide enough to sit on, at least 12 inches wide.
Related Patterns
… if all is well, the outdoor areas are largely made up of positive spaces - Positive Outdoor Space (106); in some fashion you have marked boundaries between gardens and streets, between terraces and gardens, between outdoor rooms and terraces, between play areas and gardens - Green Streets (51), Pedestrian Street (100), Half-Hidden Garden (111), Hierarchy of Open Space (114), Path Shape (121), Activity Pockets (124), Private Terrace on the Street (140), Outdoor Room (163), Opening to the Street (165), Gallery Surround (166), Garden Growing Wild (172). With this pattern, you can help these natural boundaries take on their proper character, by building walls, just low enough to sit on, and high enough to mark the boundaries.
If you have also marked the places where it makes sense to build seats - Seat Spots (241), Front Door Bench (242) - you can kill two birds with one stone by using the walls as seats which help enclose the outdoor space wherever its positive character is weakest.
Place the walls to coincide with natural seat spots, so that extra benches are not necessary - Seat Spots (241); make them of brick or tile, if possible - Soft Tile and Brick (248); if they separate two areas of slightly different height, pierce them with holes to make them balustrades - Ornament (249). Where they are in the sun, and can be large enough, plant flowers in them or against them - Raised Flowers (245) …
Reference for full-text of Pattern: p. 1124high-confidence