The area is a stretch of wetlands south of the Southhampton Estate. It serves as a fast travel marker and has a variety of mirelurks roaming around the area. In addition, a mirelurk queen will always be found in the shallow water.
- Mirelurk research - Note, on the northeastern bank of the marsh, beside a corpse and a duffle bag.
Highland Marsh appears only in Fallout 76.