Japanese Prime Minister Shinzo Abe has said he hopes Istanbul’s Marmaray tunnel project, which is being built with substantial Japanese involvement, will become a new symbol of the two countries’ friendship. The 13.6-kilometer tunnel, including a 1.4-kilometer immersed tube tunnel, which is the deepest of its kind in the world at 56 meters, is not the first mega project for which Turkish and Japanese companies have joined forces. Abe said firms from his nation would like to take part in future projects too.