Between Rosh HaShanah (Jewish New Year) and Yom Kippur (Day of Atonement, 10 days later) Jews go to a body of water, preferably one with fish, and throw bread into it. They also say a little prayer that their sins should be cast off as they cast off the bread. You can see why this is done right before Yom Kippur, a day of Judgement.
Location: Meadow Lake, Queens
After making my own Tashlich, I took those pictures of the water. Then, I was about to leave and this family came up. I was like, "great, maybe I can ask these people if I can take their picture, so it will be more 'tashlichy.'" They walked up and said to me, "do you want to take our picture?" and I realized they are one of my Shabbos hosting families. Hahahah, one of their kids recognized me from way across the park and I didn't realize it until they were right there.