Graveyard District Overview - Baldur's Gate 2
The Graveyard District will start with a fog of war throughout the zone, despite this there are no enemies in this district except for during Chapter 6 when you return to this area to take out Bodhi. I would recommend you explore all the various tombs in this zone early on during your Baldur's Gate 2 play through as the enemies in this area are low level and there are many magical items throughout for you to collect and sell for money.
Tomb of Dragomir: You will have to visit this tomb with Hexxat/Clara during the Hexxat's Request quest. This dungeon is part of the Enhanced Edition of the game.
Wellyn: During the evening and night you'll find a ghost child walking around this area, speak with him to begin the Put the Spirit of the Child Wellyn To Rest.
Tomb #2: Inside this tomb you'll find a Battle Axe +2, if you don't have Korgan in your party then you can just sell it instead of using it.
Tirdir: When you pass this area you will get a dialogue pop up on your screen; click the area next to the open grave and you'll uncover Tirdir. Speaking with him will begin the Find the kidnappers who buried Tirdir side quest.
Lower Tombs: The Lower Tombs is a location that you'll be visiting throughout the game a couple of times. During Chapter 3 and Chapter 6 you'll have story objectives to complete here and you'll also be visiting the Southern Tombs for a couple of companion quests.
Orphan: At this location you'll want to speak with Arenthis and Risa to begin the Locate a Caretaker for the Orphan Risa side quest.