This key is in the flooded district right before the Rudshore gate. Onto the right of the map facing the Rudshore gate is a small street that leads to the arc pylons . Right before, the arc plyons is a door that leads to a weeper infested building and the tenement key is right before the stairs on the other size of the building floor right next to the stairs.
Dishonored: Tenement Key
From Orcz
