Ruderates
Ruderates is a term for the excess areas that arise in regards to construction projects, which is not used, but allowed to stay as they are - and they are teeming with life! These areas have often been unmanaged in a very long time. This means that a lot of species have had time to colonize the area without being removed by humans. Therefor ruderates is an excellent example of what nature can do, as long as it is allowed. Give space and time, then the wild nature will come automatically.
So the best thing to do for ruderates is to leave them unmanaged - but not untouched! Nature is durable, and some of the many species dynamics is hard-wearing. So bring the kids and the dog for a walk and explore a myriad of life, all under 10 cm height! If you want to make your own ruderate, then use nutrient-poor mineral soil and gravel, stone and chippings in many different sizes. Then just wait and see!