Slaver Stockade Overview - Baldur's Gate 2
The Slaver Stockade is a building found in the Slums District of Athkatla. You have 2 ways of entering, the first of which is to have a Thief with high enough Open Locks to pick the front door (not recommended). The second method of entry is to enter the Slums Sewers via the Copper Coronet and travel through them to get inside the Slaver Stockade back entrance.
On this map you will find a great number of magical items (especially Composite Longbow +1) which you'll be able to sell for gold. There are also a couple of slaves that you can free for some extra EXP while exploring the area, one of the slaves (marked Captive Slave on my map above) is involved in the Free Hendak and the Slaves Side Quest.
Note: You will encounter trolls for the first time on this map when you enter the room marked 'Captive Slave' on my map above. Once a troll falls onto the ground you'll have to attack it with either Acid or Fire damage to permanently kill it.
Captain Haegan: He drops Haegan's Key which is required to open the locked doors leading to the slave cells. If you have a character with high enough Open Locks then this key will not be required.
Captive Slave: This slave is the only one you need to free in the Slaver Stockade to complete the Free Hendak and the Slaves Side Quest.
Slave 1 & 2: You can use Haegan's Key to access these 2 cells and free the slaves inside. You'll earn 2500 EXP for each slave that you free (for a total of 5000 EXP).