This trick does the following:
#Make forest disappear and be replaced by a blue glow when you character moves near it!
#Makes forest regrow when your unit moves away from area!

This makes a cool secret area for RPGs or other games! I would advise advanced deisgners to read this guide for it will come in good use on your maps! If this trick has been found before then please tell me!

This guide uses gaia forest(best forest to use) the arkantos boost sfx for the blue glow but you can change these

The following triggers are needed for it to work!

Trigger 1 (loop, active)
Conditions: always
effects: Change units in area

Select you character as the unit and set the forest as the unit to change from and titan atlantean as the unit for it to change to. Set radius from about 5 to 10 and put both players as 0.

Trigger 2 (loop, active)
Conditions: timer (1 second)
effects: change units in area

Place a cinematic block around the area of the forest and select that. Set the radius to larger that the forest area or the map itself. Put both players on 0 and make it change from invisible target to gaia forest tree.

Trigger 3 (loop, active)
Conditions: always
effects: change units in area (2)

For the first one:
Select the cinematic block again, put the radius to same as in trigger 2 whatever that was and put both players as 0. Make it change titan atlantean to invisable target.

For second one:
Same as the first on in trigger 3 except that you are changing titan gate dead to arkantos boost sfx.

Note to designers:
Please use invisable target as nothing else seems to work anywhere near as well. You can change the forest type and you can change the arkantos boost effect to any of your choice but DO NOT change the titan atlantean bit for it is need to make it work for when you place a titan you get 2 objects so you use the second object to do the glow.

There is a simplyfied version you can make where you only use invisable target and gaia forest tree (or any other forest) which will not create that cool glow.

If it doesn't work, check you are using the right objects and that everything is selected!

Please comment on this guide!