During Chapter 12 (A or B), you will start off facing a gate to the graveyard.
Turn left and follow along the path. Renee will speak a couple of times.
When you get to a fork with a gate, or more path, continue along the path.
You will see a stone-shed looking building on a hill to your left - walk up to it.
My trophy unlocked as soon as i reached the little building, but if it doesn't for you, continue up the hill past the building and turn left to see some orange netting. Walk towards this, as the lake is right there.