During the altar puzzle, wait for the bodies to be moved by the hooks. On one of the bodies, there's a statue you'll have to melee for a key.
Head downhill, and enter the building to your left. Behind that hanging body, there's a window sill with a statue. Burn the body to get to it.
Right after Joseph opens the gate, you'll end up in a market. Look for the butcher's stall (the one with hanging meat), and to the right of it, look for a stone wall. This wall has a hole with a statue inside.
