Gould Belt

The Gould Belt is a partial ring of stars local to us in the Milky Way. It is about 3000 light years across, tilted from the galactic plane by 16 to 20 degrees. It has many large and bright O- and B-type stars.
The belt may be the local spiral arm to which the Sun belongs. At present the Sun is about 325 light years from the arm's centre. The belt is thought to be from 30 to 50 million years old, and of unknown origin. Benjamin Gould identified it in 1879.
The belt contains bright stars in many constellations including (in order going more or less eastward) Cepheus, Lacerta, Perseus, Orion, Canis Major, Puppis, Vela, Carina, Crux (the Southern Cross), Centaurus, Lupus, and Scorpius (including the Scorpius-Centaurus Association). 
Overview.
Star-forming regions with bright O and B stars make up the Gould Belt. These regions include the Orion Nebula and the Orion molecular clouds, the Scorpius-Centaurus OB Association, Cepheus OB2, Perseus OB2, and the Taurus-Auriga Molecular Clouds. 
A theory proposed around 2009 suggests that the Gould Belt formed about 30 million years ago when a blob of dark matter collided with the molecular cloud in our region. There is also evidence for similar Gould belts in other galaxies.