Secret Stash Tip is a written note found in Dishonored.
Higgins, I recently got a tip about a stash, hidden at the North End of Kaldwin's Bridge. Another crazy bastard keeping all his shiny stuff in a secret room.
I was told you need to turn on the faucet in an old sink three times to open up some kind of secret door.
No information on the value of what's in this room, I only heard about a street speaker hanging over the road, just outside the door. Sorry about that, mate.
Don't forget my share if you find it.
It can be found next to a corpse on the first rooftop bridging the streets of North End during the mission The Royal Physician.