Creating a play mound in the garden - experiences

How did you imagine a waterfall for later?
Asking for a friend...

Well, quite naively:
Dig a hole at the foot, put in pond liner, shape it on the hill, and then pump water up from the pond with a submersible pump.

From that, you could simply make a babbling brook or waterfall by removing some material.

Then plant it nicely and drape with stones.

is usually just a temporary story

what didn’t we want to do and then came football and the Playstation

It is also not really practical when it comes to mowing, etc. Personally, I wouldn't do it.

It's also not really practical when it comes to mowing, etc. Personally, I wouldn't do it.

...you don't have any children either ;)

If the extra effort of such a hill doesn't bother you, why not? Even if only for a few years. During that time, the children are busy and you have some peace ... you will need the time for the garden and so on.

Before you pour, lay old concrete pipes underneath. Like a cave system.;)