Diamond of Istanbul is the tallest building under construction in Istanbul, Turkey, being built on the Büyükdere Avenue in the city's Maslak central business district of Sarıyer. It is also the country's first steel skyscraper. When completed, it will rise 63 floors above ground level and reach an above-ground height of 311 meters; thus surpassing the current tallest skyscraper in Istanbul, the 302m (60 floors) Istanbul Sapphire in Levent. The panoramic restaurant on the top-most floor will be at one of the tallest man-made points in Istanbul and Turkey.