The museum contains a letter by the Leonardo da Vinci to Sultan Beyazid II proposing a bridge over the Golden Horn:
"I, your faithful servant, understand that it has been your intention to erect a bridge from Galata to Stambul... With these words Leonardo described in a letter to Sultan Bayezid II how he would build the greatest single span bridge of the ancient world. The two different drawings, one of which is a bird's-eye view, are explained in detail in Leonardo's own hand: The bridge, which stretches from Pera to Constantinople, is 40 braccia (1 meter = 1.64 braccia) wide, 70 braccia high above the water, and 600 braccia long, in other words, 400 braccia over the water and 200 over land, and thus has its own abutments." The Sultan remained unconvinced and the bridge was not built. The letter was discovered in the national archives in Istanbul in 1952."
A recent article on da Vinci Bridge project (from a Turkish newspaper)