How to reach the Putrified Ducts in Hollow Knight: Silksong
via polygon.com
Short excerpt below. Read at the original source.
The Putrified Ducts in Hollow Knight: Silksong is one of the hardest regions to access. As our Silksong interactive map shows, the Putrified Ducts form the northeastern corner of Pharloom, but you can’t just walk over there.