Halls of Valor

The Halls of Valor (or the Hall of Valor and sometimes referred to by the vrykul as Valhalas or Valhallas) are said to be located high up in the clouds above Stormheim,  however, they are also mentioned to be above Helya's realm of Helheim. This is where the greatest warriors of the vrykul are called to serve Keeper Odyn as their eternal reward for being the worthiest.

As you are seeking out the Pillar of Creation in Stormheim, you are contending with the Burning Legion cooperating leader of the vrykul in Stormheim, the God-King Skovald. As you race against him through the region, both of your paths lead you to this dungeon, which is the location of the Pillar. You must prove yourself worthy in battle so that you can claim it. We also learn more about the origin of the Val'kyr here. These aren't the undead Val'kyr from Northrend, but the pure warrior of the Light. Its polar opposite is Helheim. The Skyhold is a section of the Halls, which are entered through the Gates of Valor.

Creation
After the proto-dragons defeated Galakrond, the keepers saw them worthy to be the protectors of Azeroth and wished to call upon the mighty titans to bless them for that purpose. However, Odyn, Prime Designate and ruler of the keepers, resented this idea. He did not trust the proto-dragons and so he sought to create his own elite army, one of steadfast and valiant stature. He saw the vrykul, children of the titan-forged, to be the most desirable candidate for his army. However, the other keepers did not concur with Odyn's aspirations and attempted to dissuade him from his plan. Odyn was unyielding to their request and continued with his scheme.

Within the halls of Ulduar, Odyn secured one of the sections to be the headquarters for his new army. He summoned the titan-forged sorceress and friend Helya and with her power, she ripped the division of Ulduar and stationed it in the misty heavens above Azeroth. This would be known as the Halls of Valor, home of the mighty Valarjar.

Imprisonment
After the corrupted keeper Loken had restored Helya's free will, she called upon the same powers she had used to secure the Elemental Plane and sealed off the Halls of Valor with an impregnable, magical barrier. She then proceeded to create Helheim as an enchanted refuge for herself and the other Val'kyr far below the Halls.

Adventure Guide
''In the clouds high above Stormheim, the titanic keeper Odyn has called the greatest vrykul warriors on Azeroth to be his Valarjar. Amidst feasting halls and hunting grounds, these ascended vrykul test themselves and prepare for the great war that is to come. Adventurers must pass through these halls and prove their worth if they hope to stand before Odyn and claim the Aegis of Aggramar.''

Achievements

 * Halls of Valor (achievement)
 * Heroic: Halls of Valor
 * Mythic: Halls of Valor
 * Mythic: Halls of Valor Guild Run
 * Stag Party
 * I Got What You Mead
 * Surge Protector

Notes and trivia

 * Since the Halls of Valor's structure was imprisoned like the inhabitants of the Elemental Plane, the structure is located within a pocket dimension.
 * During Brewfest, the Stormforged Valarjar wear Brewfast hats, and a giant beer tankard is installed near Odyn's throne.
 * The art and feel of the dungeon is heavily inspired by.

Speculation
The Halls of Valor's exact location is unknown, but since Helya imprisoned the structure like the Elemental Plane, is thus inside a pocket dimension. It is possible it is inside Skywall, given Helya's involvement in the creation of the Elemental Plane.