Impassable hexes?

[neonlicht]

In other JTS games I've bought there is an option (in the scenario editor) to place "impassable" hexes on the map. This can be very useful, and it also allows for historically accurate scenarios in which, for example, a wood or forest was deemed "impassable". But in the SYW game I can't find such an option in the "Hexes" menu. Just saying...