Docks District Overview - Baldur's Gate 2
The Docks District is home of the Shadow Thieves Guild and is one of the Athkatla districts that you will be visiting most frequently during your travels. Aside from during Chapter 3 where you'll be spending a considerable amount of time here you'll also have the Find out what happen with Montaron side quest that takes place here as well as the entire Find proof of Mae'Var's Treachery side quest chain. Both of these quest chains are ones that I would recommend you do on pretty much every play through as they're both good EXP and money. The Mae'Var chain also unlocks Edwin as a potential companion.
Aside from the side quest chains that take place here you'll also find Cromwell's Blacksmith here which is a unique blacksmith. Cromwell can make a variety of weapons and armor for you depending on what items you have in your inventory at the time. Some of the best items in the game are made by him so it's definitely worth it to check him out!
Shadow Thief Guildhall: The Shadow Thief Guildhall will be a building you'll be visiting frequently throughout your playthrough. During Chapter 3 you'll either be working with or killing everyone inside of this building. In the basement of this building you'll also find Renal Bloodscalp who begins the Find Proof of Mae'Var's Treachery side quest.
Sea's Bounty Tavern: This is the Inn of the Docks District and it's a building you'll be visiting many times for many different quests. If you have Jaheira in your party then the first time you enter this building you'll get dialogue with Baron Ployer during which he'll curse Jaheira and begin the Save Jaheira From Baron Ployer's Curse side quest.
Kangaxx's House: Inside this building you'll find one of the hardest bosses in the entire game, Kangaxx. However, before you're able to actually fight him you'll have to complete the Restore Kangaxx's Body side quest which requires you to hunt down 2 Lich enemies in Athkatla to collect Kangaxx's parts. Kangaxx will drop some of the best equipment once defeated such as the Ring of Gaxx.
Mae'Var's Guildhall: You'll gain access to this guild hall after talking with Renal Bloodscalp in the Shadow Thief Guildhall and accepting the Find Proof of Mae'Var's Treachery side quest. If your main character is a Thief then you'll be able to take control of Mae'Var's Guildhall as your stronghold in the future. Check out my Thief Stronghold Walkthrough for more information about this.
Cromwell: Cromwell is a blacksmith who can craft a wide variety of unique weapons and armor for you. I recommend you check out my Cromwell's Blacksmith Guide for more information about what he can make and what items you'll need.
Xzar: After you complete the Bring the Poisoned Man to his friends side quest Xzar will appear at this location and stop you the next time you go past. Speaking with Xzar and agreeing to help him will begin the Find Out What Happen With Montaron side quest which is a required prerequisite for Jaheria's Companion Quest.
Harper Hold: You'll be visiting this building for a couple of different side quests, Bring the Poisoned Man to his friends is the first one that brings you here after which Find Out What Happen With Montaron takes place inside of the building. Eventually you will come back to this building during Jaheria's Companion Quest.
Rylock: Rylock is the NPC you'll need to deliver Renfeld's body to for the Bring The Poisoned Man To His Friends side quest. Once you've completed this side quest you'll have to interact with Rylock again during the follow up quest, Find Out What Happen With Montaron.