World's deepest underwater railway tunnel opens 150 years after a sultan first imagined it

An underwater railway tunnel is now open between the eastern and western parts of Istanbul. The tunnel is the world's first to connect two continents: travelling under the waters of the Bosphorus strait, it joins the Asian and European halves of Turkey's largest city together. It's also the world's deepest underwater railway tunnel, sitting 190 feet (58 meters) below the surface of the Bosphorus.

via Tech News Headlines - Yahoo! News http://www.theverge.com/us-world/2013/10/30/5045174/istanbul-railway-tunnel-is-worlds-deepest-connects-asia-europe