This year the MIT class ring, the Brass Rat, hides a hackers' diagram of a subterranean campus wide tunnel network.Networks of secret passages and tunnels have been built on a giant scale, from components of the Maginot line to the Viet Cong Cu Chi Network. Others perform a peacetime function, such as the half mile tunnel network H.G. Dyar built under his Washington home, as a hobby, the passageways under Disney's Magic Kingdom or the unbelievable 5000 year old Lizard People tunnel network under Los Angeles that the L.A. Times published a diagram of during the depression.Here is a collection of our favorite tunnel network diagrams, drawings or models.