Rescue on Mount Arreat (quest)

From Diablo Wiki

Look for three pens in the Arreat Plateau. Once you destroy the door to the pens, a portal will open to lead the prisoners to safety. The prisoners can be killed, so be careful. A minimum of prisoners need to be rescued alive, but most people should be able to rescue all of them.

Diablo II and Lord of Destruction quests
Diablo II quests
Act I — Den of Evil • Sisters' Burial Grounds • Search for Cain • Forgotten Tower • Tools of the Trade • Sisters to the Slaughter Act II — Radament's Lair • Horadric Staff • Tainted Sun • Arcane Sanctuary • The Summoner • Seven Tombs Act III — The Golden Bird • Blade of the Old Religion • Khalim's Will • Lam Esen's Tome • Blackened Temple • The Guardian Act IV — Fallen Angel • Hell's Forge • Terror's End
Diablo II: Lord of Destruction quests
Act V — Siege on Harrogath • Rescue on Mount Arreat • Prison of Ice • Betrayal of Harrogath • Rite of Passage • Eve of Destruction