Hellgate Keep

Hellgate Keep, formerly Ascalhorn, was a city of evil on the northeast edge of the High Forest. It was destroyed in 1369 DR when the Harpers used the Gatekeeper's Crystal, and is now overseen by the treant Turlang and his fellows.

Ascalhorn
Ascalhorn was founded by the Eaerlanni elves in the northeast of the High Forest on an area known as Ascal's Horn, to protect the boundaries of the kingdom. They gave it to the Netherese refugees after Netheril fell.

Wulgreth, a Netherese wizard, summoned demons to the city in 820 DR. In 880 DR, this prompted other wizards, with the guidance of the fey'ri, to summon devils to counteract the demons, but in 882 DR the demons won the battle and conquered the city. The demons continued their rampage, destroying Eaerlann and Ammarindar.

Hellgate
In 886 DR, Harpers placed wards around the keep to prevent demons from using their gate abilities.

In 1368 DR, the Blue Bear tribe, led by shaman and chieftain Tanta Hagara, marched on the fiend-ridden fortress.