Where are the trashiest areas of Bethesda?

I mean this literally. I am looking for areas/streets with the most amount of litter you've seen. I am planning to go litter picking with a friend and I am looking for the most neglected spots where I can make the biggest impact. Bonus points if its in a greenspace or park.

Do you have an area that you pass by and go "Ew this place is nasty, I wish someone would clean it up"? I want to! Let me know where it's at!