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.
Since its completion in 2010, the world's tallest skyscraper has been Burj Khalifa in Dubai, United Arab Emirates. The building, which was designed by the architects Skidmore, Owings & Merrill, is a mighty 828 meters tall and has 163 floors. Burj Khalifa is one of Dubai's most famous buildings.