Depths of the Underdark - Links and Additions

Depths of the Underdark by Ninden is probably one of the most ambitious custom dungeon mods ever created for Oblivion. It adds a huge number of diverse locations, connected through a large network of passageways, that altogether form a vast underground labyrinth, laid out in a geometrically consistent fashion. While the dungeon is very impressive in its present form, the project was unfortunately seemingly abandoned, leaving many of the new areas in a somewhat barren condition.

The main purpose of this mod is twofold:

1. Flesh out some of the empty areas and bring them to life.

2. Add connecting passages to dungeons from other mods in places where this makes geographic sense, forming one gigantic mega dungeon.

Additions: 

The previously empty Subterranean Stronghold is now inhabited. It has been claimed by a band of soldiers under the command of Lord Urzag, Warden of the Deep Halls, and now forms an outpost of the empire, that keeps the hordes of the undead that inhabit the Underdark in check. A colony has been established there, that includes merchants, miners, traders and shopkeepers of all races, as well as a Mage Guild chapter. Adventurers exploring the Underdark may seek refuge here, sell loot, restock supplies or rent a room. All inhabitants have fully fleshed out schedules, eat, sleep and go about their business in different areas of the Stronghold. The adjacent Dwarven Mines are now being worked by an Orcish mining operation.

The doors of the Hero's estate are now locked. Anyone wishing to claim it as their own, must first discover the fate of its previous owner.

Several new areas have been added to the Underdark, some of which contain passages to other dungeons from the base game, such as Rielle or Underpall cave. While their main purpose is to serve as transit locations that connect to dungeons from other mods, many of these areas are interesting in their own right.

Links: 

The Depths of the Underdark cover a large area in central northern Cyrodiil, with several entrances to the south and southwest of Bruma. As it so happens, many dungeons from other mods are also located in this area. Through a careful survey of the layout of these dungeons, several points have been identified where they may be linked up with the Underdark in a sensible way. At present, connections have been created for the following other mods:

Brandon's Dungeon Arc'Alm

Better Cities

Dungeons of Tamriel Updated

HESU KoyoTown

Ancient Dwemer Ruin Vornhuzduc

The Well Diver

Great care has been taken to ensure geographic plausibility. While dungeons are never exactly true to scale even in the base game, I find it to be of great importance that a player travelling e.g. a large distance in the north-western direction will actually end up there. I believe this was achieved