Temple District Overview - Baldur's Gate 2
The Temple District of Athkatla is one of the biggest districts in the city because it has an entire sewers system that runs beneath it which you can explore. In this district you'll also find Dorn, a companion added into the game during the Enhanced Edition. Keldorn is another potential companion that is found in this district, you can find him in the Temple District Sewers.
Aside from the 2 companions found here the other most notable thing in this district is the long quest chain that begins with Gaal in the center of town. The first quest in this chain is Investigate and Destroy the Cult of the Eyeless which is a very important quest because it unlocks the Lower Reaches, Ghoul Town and Pit of the Faithless maps for you. Completing this quest will also allow you to accept the Gain the Services of Sir Sarles for the Temple and the Another Mission for the Temple side quests.
Temple of Helm: You may be visiting this temple as part of the Investigate and Destroy the Cult of the Eyeless side quest depending on your character's class and alignment. Inside the temple Lothtyran will provide you with temple services along with selling you a variety of magical items.
Lathander Temple: You may be visiting this temple as part of the Investigate and Destroy the Cult of the Eyeless side quest depending on your character's class and alignment. Additionally, during the Find Proof of Mae'Var's Treachery side quest you may be tasked with stealing a Statuette of Lathander from inside of a locked safe in this temple. If you need temple services speak with Kreel inside, he sells various useful magical items as well.
Temple of Talos: You may be visiting this temple as part of the Investigate and Destroy the Cult of the Eyeless side quest depending on your character's class and alignment. Depending on your Reputation you may also be tasked with stealing a necklace from Weathermistress Ada from this temple during the Find Proof of Mae'Var's Treachery side quest. Weathermistress Ada is also who you'll want to speak with if you need temple services or if you want to check which magical items are for sale here.
Gaal: Your first time passing through this area there will be a scene with Gaal and some other NPCs after which you'll be approached by one of the 3 temples in this district. Which temple changes depending on your alignment and whether or not you're a Cleric. After being taken back to one of the temples you'll be offered the Investigate and Destroy the Cult of the Eyeless side quest.
Guarded Compound: This building is not involved in any quests but it does have a lot of magical items and a somewhat difficult fight on the 2nd floor. You'll find a group of adventurers and some traps on the 2nd floor, save and be careful before taking on this fight. Defeating the enemies will get you the following items... Leather Armor +3, Short Sword +2, Celestial Fury, Katana +1, Full Plate Armor +1 (X2), Large Shield +2, Gift of Peace, Battle Axe +2, Two-Handed Sword +2 (X2), Helm of Charm Protection, Adventurer's Robe, Plate Mail +1 and Mace +2. In addition to these items there are other magical items you can find in chests and containers throughout the house. I will not list them all as we'll be here all day. Suffice to say, this is a very good house to hit up for some extra money and loot.
Radiant Heart: There are a couple of NPCs inside of this building that you will be visiting for different quests. Keldorn may also wait for you in this building during his companion quest depending on the choices you make. Prelate Wessalen is one of the NPCs you'll be visiting here during the Mage Stronghold, Paladin Stronghold and Anomen's Companion Quest. Ryan Trawl is the other important NPC in here. Speaking to him will begin the Seek out and investigate the Fallen Paladins side quest and you'll also be visiting him during Anomen's Companion Quest.