You can walk through the closed NORTH-GATE-OBJ

>LOOK
North Gate
This small open area stands at the old north gate of the castle, now badly
rusted. Through the gate, a forest can be seen. To the west, a hall glows with
light, and to the south, the dark castle can be reentered. A narrow passage to
the east leads to the base of the northeast tower.

>REZROV GATE
The rusted north gate magically creaks open far enough for you to leave.

>NORTH
Forest
You are in a dark forest, just north of a rusted gate. Except to the east and
south, the forest is thick all around you.
Discarded beneath a nearby tree is a slightly crumpled scroll.

>CLOSE GATE
The gate is now closed.

>SOUTH
North Gate
This small open area stands at the old north gate of the castle, now badly
rusted. Through the gate, a forest can be seen. To the west, a hall glows with
light, and to the south, the dark castle can be reentered. A narrow passage to
the east leads to the base of the northeast tower.

>NORTH
The gate is rusted shut.

That's because while the exit from NORTH-GATE to FOREST-1 is

      (NORTH TO FOREST-1 IF NORTH-GATE-OBJ IS OPEN
        ELSE "The gate is rusted shut.")

the exit back from FOREST-1 is simply

      (SOUTH TO NORTH-GATE)

the-infocom-files / enchanter

You can walk through the closed NORTH-GATE-OBJ #15