The area itself however is quite small, and not often used for Magic Finding for this reason. The Mausoleum is also the first place with an area level of 85 on Hell, meaning that any item can drop there from champion or unique monster (and their minions) - it also contains only Lightning immune monsters, so some elemental characters might benefit from going there. In game, the Forgotten Tower only refers to the first entry level, which is just a small room with a ladder down.
Finding the Forgotten Tower and killing The Countess is required to complete the fourth quest of Act I in Diablo II, appropriately named The Forgotten Tower as well. The Mausoleum is a building that can be found on the Burial Grounds which the player travels to for completing the Blood Raven Quest. The Forgotten Tower, also known as the Tower Cellar, lies in the Black Marsh.