The game's world is divided into two parts: the above-ground and the underground ones. Each cell of the Podzemlje duplicates each cell of the above-ground Kingdom and has the same coordinates with mark # For instance, Kingdom 36-12 corresponds to Podzemlje 36-12#.
When in the Kingdom, click the navigation button:
You will be instantly transported to the Podzemlje:
The same button is used to return to the Kingdom.