Haffingar Stormcloak Camp resides on a rather precarious ledge off the road from Solitude to Dragon's Bridge. It overlooks a river running southwest of Solitude. It contains several Stormcloak soldiers and a rather grumpy commander, Istar Cairn-Breaker. They will not attack the player if the player is not a member of the Imperial Legion.
The Quartermaster will buy and trade Weapons and Ingots. There are several work stations in the camp, such as: a Wood Chopping Block, a Workbench, a Grindstone, an Anvil, an Alchemy Lab and a Cooking Pot. Near the Alchemy Lab resides a chest with variable loot inside.
Note that this site may not exist unless the Civil War Quest is active. A great use for the camp, if the Imperial side in chosen in the Civil War, is to kill all the soldiers and then use the un-killable captain to train your block and attacking skills.
If training block, make sure you don't have a follower with you, because the follower will attack the captain while you hold up your shield.