Ha-Ha and simulation ...
|a cross-section of a ha-ha|
An interesting concept and worth considering, here you can have an area for free roaming learners to do as they wish without recourse or fear of 'damage' yet in the centre, the ha-ha surronds the area that they must not touch.
The ha-ha could be a literal domain or metaphorical, with the ha-ha of a networking student being the practice of configuring routing tables. Where the ha-ha protects them from wandering into the real-world and upset the real routing tables of a live network.