A hallucination is a perception in the absence of external stimulus that has qualities of real perception. Hallucinations are vivid, substantial, and are perceived to be located in external objective space.
Construction begins on Poland's tallest tower by Foster + Partners. Work has started on a 310-metre-high Warsaw skyscraper by Foster + Partners, expected to become the tallest building in Poland. The Varso Tower, or Warsaw Tower, is now under construction on a brownfield site next to the Warszawa Centralna railway station, with completion slated for 2020.
The tallest structure in the world is the Burj Khalifa skyscraper at 829.8 m (2,722 ft). Listed are the tallest structures in the world: guyed masts (such as telecommunication masts), self supporting towers (such as the CN Tower), skyscrapers (such as the Willis Tower), oil platforms, electricity transmission towers, and bridge support towers. This list is organized by absolute height.