That's the location of a little girl, Vin (and her dog, Dotty)…
She has a quest for you: Blown Away. Take it!
All you have to do is find five balloons that've blown away from her. It's easy peasy!
They're all around Stormwind but I found all of mine in the Mage Quarter. They all look the same and they all sparkle and look like this:
Look for them in corners and alleys, too!
When you've found five then you get an Alliance Balloon of your very own! It's super fab!
And! You'll make Vin very very happy! Yay!