The Testinghall is the name of a hidden location somewhere high in Oblivion's sky which can be accessed only via the coc testinghall console command through the Wizard's Tower glitch or With the paintbrush glitch . The hall was designed as an area for the game developers to test elements of Oblivion before placing them in the game world. The testinghall is a large hall with doors leading to warehouse rooms and open areas where all possible game play elements and items can be found. They include:
- Unlabeled room (simply said "wooden door to" – this room is not labeled and is small, containing labeled crates and chests that have all of the official items in the game, including many if not all quest items. Sigil Stones of varying effects and power can also be found here, as well as enchanted and leveled items.
- Armor warehouse – housing all armor items in Oblivion
- Weapons warehouse – housing all weapons
- Clothing warehouse – housing all clothing items (including Uriel Septim's attire)
- Book warehouse – a library of Oblivion's books
- Creature Grove – an open space area with all of Oblivion's animals and creatures in it
- Lock pick warehouse – a room full of locked gates
- AI testing warehouse – a room with NPCs to test AI functions
- Alchemy warehouse – a room with all alchemy ingredients inside it
- Container warehouse – a room full of containers
- Lighting warehouse – a dimly lit room with an array of light sources to test their lighting effects
- Hawkhaven – A test town with at least one guard, a merchant with a lot of gold and some items for sale, and a few various test NPCs, a place to create Black Soul Gems, with enterable test buildings.
- Vampire warehouse- small room where you can become a vampire and feed on someone.It is also a "wooden door to".
It must be noted that not all of the rooms in the testing hall are used - most unlabeled wooden doors are inactive. The easiest way for the player to return to the Tamriel world is to go through the door labeled "to Hawkhaven", where you can fast travel from, or via the "coc" console command.
It must also be noted that inside the Testinghall there are weapons that were most likely removed from the game, but are still available. One of them includes the Mace of Doom, a highly powerful mace that is also a leveling weapon. It has the effect of Fire Damage in a radius for a certain amount of seconds, depending on your level, skills and attributes. The mace does not have a menu icon, nor a First or Third Person placeholder. However, it appears to the user in the menu as an Ebony Mace.