The forest is known to be dense and unmarked by trails. Apparently, the woods used to be much larger, enough to cover majority of the lowland of the country before most of it was cut down to make way for the city, as well as to clear out the wolf packs and vampire nests.
In 1984, Valentine Morgenstern's father was apparently killed by a werewolf in the western edge of the forest. In the following months, Valentine made several hunting trips to the forest with his Circle followers in hopes of finding the werewolf that killed his father. During one particular trip, Valentine was with Robert Lightwood and Michael Wayland when they infiltrated the Silverhood manor in the forest, which was being used by a family of werewolves as a home.
While Shadowhunters and Downworlders prepared for the war against Valentine's demons, vampires led by Raphael Santiago at that time settled in the forest and refused to cooperate with the Clave against Valentine unless they surrendered the Daylighter Simon Lewis to them. Simon decided to meet with them in the forest and was accompanied by Maia Roberts. Luke also reunited and allied with his old pack for the war.
Diana Wrayburn had seen a circle of blasted nothingness in the center of the forest. The land was like ash and trees were burned to stumps, as if acid had charred away everything living. Gwyn ap Nudd had described it as a blight caused by dark magic only seen in Faerieland. When Diana brought it to the attention of Jia Penhallow, the Consul, she was told that Helen Blackthorn and Aline Penhallow had seen something troubling in the area of Brocelind. There were dark spots on the maps of Alicante as if the very trees had been practicing evil magic. At that time, Jia and a team rode out to see for their selves, but saw nothing.
Not long after their talk, Jia and Diana went to the forest to see if their Seraph blade's worked in the blight. As soon as Jia stepped into the blighted circle, the Adamas in her blade died out. When she stepped out of the circle, the blade blazed with light, as if a switch had been flipped on. Jia described being in the circle as cold as ice with despair hanging in the air. It was found that the blight was caused by the Unseelie King but not why or how.