Ulduar is a raid dungeon in the Titan complex of Ulduar, located within the The Storm Peaks. It serves as the prison of the old god Yogg-Saron as well as the current residence of most of the titanic watchers who have fallen under his influence. It is notable for its interactive ways of starting hardmodes--instead of switching the difficulty of the encounter before fighting, players would have to start the encounter in a certain way to unlock the hardmode. For example: defeating Thorim's gauntlet in 3 minutes or less would trigger his hardmode.
The Yogg-Saron hardmode is especially notable for having varying degrees of difficulty. In the basic version of the encounter, players receive assistance in the form of buffs from all four Keepers. If players do not speak to a Keeper before pulling Yogg, they will lose that Keeper's buff.
Ulduar also has an extreme amount of achievements associated with it. There are numerous ones that are not required for the meta-drake. In later dungeons, the number of miscellaneous achievements was toned down.
Along with Uldum and Uldaman, there exists a third base of the titans called Ulduar. A fourth base, Maraudon, is the location of Terramok, an ancient titan vault. A fifth base is located under Bael Modan. Ulduar is located in The Storm Peaks of Northrend.
Ulduar is a mysterious subterranean realm of ice and stone. This was once thestorm giants' stronghold, but they didn't build it. Brann Bronzebeard believes it to be a titan city (it is also a production facility and prison), as it matched the design of the two temples in Northrend and other ruins dwarves found elsewhere (and because it contained the word "Uld"). Massive buildings protrude from the tops and sides of mountains, many hundreds of times taller than a human. When Brann Bronzebeard first explored the area, a section he discovered was covered in rock and ice. He thought it was an amazing place but couldn't tell from outside, because it was completely hidden to him. The exterior he saw looked like the other peaks to him: a jumble of rock and ice cut at angles only nature would have produced. The entrance he discovered was well-hidden and heavily guarded by crystal golems. However large sections of the facility are now visible aboveground.
Inside, Ulduar is a profusion of tunnels and stairs and balconies. The entire place appears to be carved out of a massive cave, and many of the levels are natural ledges. It has the feeling, as if nature were improved upon rather than replaced or recreated. The surfaces are a strange mix of smooth and unaltered stone and ice, as when a master sculptor works in stone and lets the material¡¯s natural texture add depth and beauty. It shows where the dwarves got their skill in stonework, but judging by Ulduar they're still a long way from matching their creators.
When Brann was exploring the place, the storm giants themselves were so few in number that one could wander the halls without ever meeting one ¡ª he believed this was probably for the best, since no one was supposed to gain entrance. The giants are a dying race desperately avoiding their fate. They seem to think another race will vanquish them some day, and so they hide in Ulduar rather than girding for battle. They are too frightened to battle theScourge, but apparently they hate it. Ulduar is likely a treasure trove of information on the Titans and their activities. Since then the storm giants have moved to the Howling Fjord.
For millennia, Ulduar has remained undisturbed by mortals, far away from their concerns and their struggles. Yet since its recent discovery, many have wondered what the structure's original purpose may have been. Some thought it a city, built to herald the glory of its makers; some thought it a vault containing innumerable treasures, perhaps even relics of the mighty Titansthemselves. Such speculations were wrong. Beyond Ulduar's gates lies no city, no treasure vault, no final answer to the Titan's mysteries. All that awaits those who dare set foot in Ulduar is a horror even the Titans could not, would not destroy, an evil they merely... contained.
Beneath ancient Ulduar, the Old God of death lies, whispering.... Tread carefully, or its prison will become your tomb.