Children love to make houses, from whatever it takes - a blanket stretched over chairs, a large package from household appliances will do. On the playground in the house you can hide from the whole world and create your own, special little cozy little world.
For older children, the house should be more solid, so that you can walk to the full height, put the furniture for the children, hold the light there so that you can play in the evening.
To put this structure on high stilts, enter the steep ladder, and you can go down the hill. Under it is a sandbox, toys are stored - it turns out a real playground with a house on it. To build one, some building skills are needed, of course. But the children will be happy to play here, and not one year.