Can’t find a switch in Cave 2

(Phantasy Star Online Episode I & II, GameCube)

In most (or all?) map variants of Cave 2 there is a barrier blocking the way to two brownish boxes. It’s in the corner of a room with a little lake and waterfall, if that helps. It’s a usual barrier where you have to find the corresponding switch, but I did not manage to find it.

It’s in the Cave 2 map of the quest Secret Delivery, too. I marked the spot in the map (from PSO World):

Is the switch hidden somewhere?

Okay so I found it. It's a step switch which is in the very same room, hidden under some bushes on the other side. This is the map variation I had when I found it.