Originally Posted by Pessimeister 
Durlag's tower is one of the most challenging and enjoyable dungeons in the BG saga fullstop.
I daresay that Durlag's tower is the best designed dungeon I have ever played. I loved every second of it. It is beautiful, challenging and if you choose to read the lore about Durlag and his demise you will find out that it has some Shakespearian quality to it.
It still shines above anyting that Bioware has done since.