Great Problems for Writing in Math?

A few weeks ago, I did a workshop for Forsyth County as part of their Literacy Design Collaborative training. I worked with math, science, social studies, and CTAE teachers on content area reading and writing. While there, the math cohort introduced me to a great resource for problems that included writing in mathematics. The site contained released performance tasks from a standardized test, but I can’t remember which one! If anyone from the Forsyth training knows what I’m trying to remember, please drop me a note.