The small-scale version of the rain garden: very pragmatically designed here in the streetscape of Copenhagen. The surrounding steel edge has an opening through which rainwater from the adjacent sidewalk flows into the swale. Several of these swales are connected by small pipes to create a larger retention volume. The polygonal shape is very flexible and can adapt to various existing situations. Birch and pine trees have even been planted in the swales, but there is also a drain in the bottom to prevent the water from stagnating for too long.