They say it's the tap water they have bottled and shipped here from NYC and maybe it is or maybe it's just bomb ass pizza made by good people who now how to create and maintain a great reputation. Everyone knows it's there and I usually always get a slice or two when I have an appointment in the east tower and that makes going to the cosmo for any reason that much better. Secret pizza is a must stop for everyone so plan on standing in the line for a few minutes. You'll realize that it was time well spent with in your first bite.