Narbondel

The Narbondel was a huge stalagmite in the city of Menzoberranzan and served as a clock for its inhabitants. It was located in the district of Narbondellyn.

History
At one time, the drow Zaknafein Do'Urden found Menzoberra's tomb within Narbondel and took the Dagger of Menzoberra back to the city.

During the Time of Troubles in 1358 DR, the clocktower was bathed in searing flames which blinded those who looked upon it with darkvision.

Structure
Narbondel was the only unshaped piece of stone within the boundaries of the city cavern and it was used as a clock. The heat from the Archmage's spell formed a band around it and moved up, taking twelve hours to reach the peak, before travelling down it again, going out once it reached the base.

At the end of every day, the Archmage of Menzoberranzan cast magic upon the stone to heat it. This heated point climbed the stalagmite during the day and showed the drow the passing of time. At the end, the stone glowed red before it cooled down rapidly and the archmage renewed the magic. When the pillar was completely dark, it was called Narbondel's Black Death (effectively midnight).

Tomb of Menzoberra
Besides being the clock of Menzoberranzan, the stone pillar housed a much greater secret. Within the stalagmite, the ancestors built the tomb of the legendary founder of the city itself, Menzoberra the Kinless. From a top of the pillar, a secret stair lead to the hidden chamber where the body of the priestess once lay in a cocoon upon a huge spider's web spanning a tremendous abyss. When Zaknafein took the Dagger of Menzoberra, the spider's web crashed and the cocoon with the corpse fell into the depths.