The herbalist's house is shown as a place of interest on The Witcher map, but nothing of any consequence happens there. Geralt can have a conversation with herbalist in the middle of the night which is somewhat revealing of the situation with Salamandra, but not terribly.
The house itself is located adjacent to the Maribor Gate in the Trade Quarter and can be easily identified due to the placement of a statue depicting the goddess Melitele.
Notes[]
- It is unclear if this is the same "Viziman herbalist" whom Geralt meets in the Outskirts, but likely.