Burj Khalifa's Secret

The Burj Khalifa, the world's tallest skyscraper, stands on sand without any bedrock. Its base is supported by a massive concrete slab, which acts like a snowshoe and prevents it from sinking. 194 shafts of concrete were dug into ancient seashell dust to provide friction, and it is the only thing holding up the building. Despite its towering height, the Burj Khalifa is not connected to the municipal sewage system, and its waste water is transported out of town by trucks, which sometimes have to wait in line for up to 24 hours.