Druids of Doom (1982)

From the web:

The House of Euklidies, a temple to Astokph the Deity of Travel and Transporter of the Dead, is asking for a group of adventurers to recover three lost magical items of the temple. Adventures must pass through the portal and enter the Druid's Keep to recover them. Contains 6 maps, 5 new monsters, and over 60 NPCs. 

Players must teleport into the Druid's Keep and recover 3 artifacts - ideally without harming the druids, but the recovery of the artifacts is of primary importance.