No painting! (on the wall, you can supplement it according to the situation after you get something. )

Don't throw peels about.

No littering! (In foreign countries, you can simply say this, don't be scared by this kind of thing.)

Please?Keep?Off?the?Grass?

Please don't trample on the lawn! (that is, stay away from the lawn! )

Please don't chop and change.

Don't destroy trees! (Foreign countries say, don't cut down trees indiscriminately)

It can't be wrong, don't worry.