Rough Neighborhood - Novigrad
Location: Oxenfurt (Near Western Gate)
Quest Giver: Dora
Other Requirements: Once you've accepted the quest don't get too far away or you'll fail
In order for this quest to become available you must first complete Contract: The Oxenfurt Drunk. To begin this quest you will want to travel north from the Western Gate Signpost in Oxenfurt along the road until you run into the woman being harassed (pictured above). She will only be outside at night and if you get close enough to her to trigger this event then leave the area you'll fail this quest.
Use my map below if you need help finding this quest location. When you discover Dora you'll need to intervene and fist fight the three men that are harassing her, she'll tell you that you she could have handeled herself and you will have the option of walking her home. Do so for more EXP as well as an extra bit of story once this quest is over.
Once you drop her off the quest completes - but there is one last thing you can do. It gives some EXP and a bit more story. South of the Western Gate there is a small courtyard and in that courtyard you'll encounter a small group of bandits. When you fight them Dora will come running out to help you and talk to you after the fight.
Note: To get the bandits to appear, fast travel anywhere then go south of the Western Gate.