From Guild Wars 2 Wiki
Unlit Torches can be found in the southwestern part of Kusini Crossing. They can be lit using the nearby torches.
- The torches have no nameplate, which may make it difficult to find them.
- Upon completing the task at night, a large Forgotten Treasure chest will spawn between the large columns in the lit corner of the halls (i.e., the circular area full of sand sharks). You will be notified in text chat, reading "All torches have been lit! A chest has spawned on the pedestal." in yellow letters.