Leonardo da Vinci Sketches the Design for the Golden Horn Bridge

In 1502 Leonardo da Vinci produced a drawing of a single span 720-foot (240 m) bridge over the Horn as part of a civil engineering project for Sultan Bayezid II. The vision was resurrected in 2001 when a small footbridge of Leonardo's design was constructed near Ås in Norway.

On May 17, 2006, it was announced that the prime minister of Turkey Recep Tayyip Erdoğan and the mayor of Istanbul Kadir Topbaş had decided to resurrect the Leonardo da Vinci Bridge project. The urban planning and feasibility studies of the project had started earlier, in 1999. After five centuries, Leonardo da Vinci's bridge will span the Golden Horn, becoming the first architectural project of the Renaissance genius to be realized in its original scale and its planned location.

The Turkish architect in charge of the construction is Bülent Güngör, known for the restoration of the Çırağan Palace, the Yıldız Palace, and the Sümela Monastery. The Bridge will be an exact copy of da Vinci's design, with a single span of 720-foot (240 m), a width of 8 metres, and a height above the Golden Horn of 24 metres, as shown on his sketches.

http://en.wikipedia.org/wiki/Golden_Horn