The Gould's Belt was first described by Benjamin Gould in 1879 as a collection of bright and massive stars that formed a ring in a projection on the sky. It turns out that the region traces out several molecular clouds in the local part of the galaxy where star formation is prominent. The Gould's Belt Survey hopes to discover new forming stars that are enshrouded in the molecular clouds by using the Spitzer Space Telescope in collaboration with two other teams who are employing the JCMT and Herschel observatories. Gould's Belt is quite vast and is estimated to have a diameter of 3000 light years. In Earth terms, that is roughly 18,000,000,000,000,000 miles or 28,000,000,000,000 km.
Check out the image below to see the distribution of the Gould's Belt on the sky. The area highlighted in orange illustrates the Belt shown against the disk of our Milky Way galaxy, which contains our Solar System, as well as the entire Gould's Belt. In fact, the Belt is relatively close to our Solar System. The Galactic Center is approximately 16 times more distant than the furthest clouds in Gould's Belt. Click on the image to see a larger version.