Diamond Tower is a landmark skyscraper under construction in Cairo, Egypt. The building will be the tallest in the Arab world and the 31st-tallest in the world when completed. The tower is designed by the London-based architecture firm Foster + Partners, and is expected to be completed in 2018. The building will feature a steel frame and an exterior facade of polished diamond-shaped glass panels. At , the tower will be the tallest building in Cairo and the Arab world, and the 31st-tallest in the world. The building will have a total floor area of and will be home to luxury apartments, a hotel, a shopping mall, and a public observatory.