From Destinypedia, the Destiny wiki
Miasma is a swampy region of Savathûn's Throne World that is under the sway of the Scorn. It is littered with ruined Hive structures and Scorn constructions. Its northeast side features a dirty, muddy path that leads into the Florescent Canal region and runs under collapsed Hive fortress walls, suggesting that the Scorn created the path originally by tunneling under the walls of the Hive fortress and breaking in, similar to techniques used by Medieval warriors to assault a castle.
List of appearances