Skyforge (Skyrim)

History
The Skyforge is an ancient forge located next to Jorrvaskr in Whiterun that is said to be older than men and mer.

It was discovered by Jeek of the River and his crew who were traveling south from Hsaarik Head to settle. They scouted the area later named Whiterun Hold and found a mysterious structure that was described as "a monument of a bird whose eyes and beak were opened in flame". It was discovered that the monument was feared by the native elves and suspecting that it held great power, Jeek and his crew settled and built Jorrvaskr at the foot of the Skyforge.

The Underforge
Under the Skyforge is the Underforge where The Circle meet and pray to Hircine. There is also a passage to the right of the stone bowl that leads to a secret exit out of the city. It is here that the player is inducted into the Circle by a blood ritual involving Aela the Huntress and Skjor.

Resident Blacksmith
The forge is used mainly by Eorlund Gray-Mane to craft armor and weapons for the Companions. Completing the quest Proving Honor will allow the player to receive a skyforged weapon of his/her choice, handcrafted by Eorlund.

Skyforge Smithing
Here is a list of weapons and armor that can only be smithed at the Skyforge after completing The Companions questline.

Note: The options to craft the weapons will show up in the Draugr subsection.

Note:  The options to craft the armor will show up in the Daedric subsection.

Skyforge Weapons
Here is a list of the Skyforge weapons Eorlund has for sale.

Trivia

 * Damage seems to be higher than that of Daedric weaponry (At least when improved to appropriate levels using Smithing perks) while Wolf armor seems to have a negligible difference between Daedric armor. These make them very viable alternatives if ones character specialized in Light Armor Smithing but still needed powerful Heavy Armor (Perhaps for a follower who skills lie in an alternate armor class)
 * It should also be noted that you can obtain a Skyforge weapon from any fallen member of the Companions. Also, It is possible to obtain a Skyforge Steel Greatsword from Farkas during the quest Proving Honor after he transforms back to human form. He will not pick it back up, instead, he will equip an Iron Greatsword.
 * It is possible to pickpocket Vilkas' Skyforge Greatsword with the pickpocket perk Misdirection.
 * You can use a passage to get on top of the Skyforge by going under Whiterun.
 * You can climb on top of a house and onto the walls that are INSIDE Whiterun, on the pillar-like wall, then jump on the walls then clip through it, when you clip through the wall, you can get out of Whiterun and run around Whiterun to the back of the Skyforge, behind the eagle that overlooks Jorrvaskr, you can clip through a part of a rock, then you can see a chest with good armor and weapons inside the rocks, that is below the Skyforge.
 * Referring to the above, this chest actually seems to be Eurland's store stash and store money.
 * After Kodlak's funeral, the player can craft Ancient Nord Armor and Nord Hero Weapons at the Skyforge.
 * There is also a rather obvious skill book for Smithing beside the Skyforge itself.

Bugs

 * The Skyforge Dagger cannot be improved using the grinding wheel.
 * (360)On rare occasion, when fast-traveling to Whiterun, large parts of the Skyforge/Underforge will not load, allowing you to fall through the map 10 or so feet, where you can then run around underneath Jorrvaskr and run outside of Whiterun (you may not interact with anything outside the Whiterun walls, since only Whiterun and everything inside is loaded. You may not open any doors, and no enemies will be found anywhere). Eorlund Gray-Mane will be found dead underneath the hidden chest/Eorlund's store supply where the Underforge should be. Reloading a previous save fixes this.