Finding the Chapel Key
Search near Mushroom Village for the illusion-marked stone arch and statue area. Slow down around environmental transitions; the route is easy to pass when treating the area as ordinary scenery.
What the key unlocks
Use it to enter the Shrine of Trials route. The reward chain is significant enough to combine with an early Fainweald exploration sweep rather than making a single-purpose trip.
Crypt Key planning
Track the Crypt Key in the same checklist because both keys act as route gates. Mark the door as well as the pickup so you know whether the remaining task is discovery or use.