While architectural features are oftentimes more aesthetic than they are technically complex, this still seemed like a suitable question for here.
I am working on a project for an industrial type facility that will include one or more large exhaust air stacks. These stacks are part of an odor control system, so while the air will be clean, the final step is to get the air high over the area for the purposes of dispersion. The facility will be in a relatively nice part of town so the residents don't really want to see the stack. Are there proven ways to hide such a structure or to make it more appealing similar to what is done with cell towers disguised to look like trees?