It is known as the largest abandoned structure in the world, and even once the tallest hotel anywhere. Known as the 'Hotel of Doom' the Ryugyong hotel in North Korea sure has an interesting story, dating back to 1987. The building stood as a 330-meter tall, empty concrete pyramid for 18 years before the shiny windows were applied. While construction has halted and restarted many times, it is still unknown when the hotel will be finished, though many are hopeful that it will be soon.