A three-dimensional map of the Milky Way based on classical Cepheids

We present a three dimensional map of the Milky Way based on a sample of 2431 classical Cepheid variable stars. The distances were determined with the use of mid infrared (IR) data from the WISE and Spitzer telescopes. We show that the Galactic disk is significantly warped and flared. We also present a simple simulation that shows that Cepheids were born in episodes of star formation in the spiral arms.