Dynamite is used to instantly clear a large area of land without using energy.
Tap on the dynamite and choose the spot near the area that you would like to clear. After placing the dynamite, you will see the highlighted area showing which obstacles will be removed.
 
How to place the dynamite?

Tap on the dynamite icon and then select the spot where you want to place it. If it's not possible to place it, the dynamite will be blinking.

Try moving the dynamite slightly until the blinking stops.