We're coming to this fascinating town every year and we still love it, so we might be of another kind. The trouble with Istanbul is where to begin, for most of the town is interesting and a lot has been written in travel guides and other books already. The only thing I can provide is information that is not so readily available.
Every travel guide provides information about that.
Instead I'll try to point to special things about those monuments, best times to visit and things to look for. On top of that a tunnel will be constructed. The bridges are not the only means to cross the Bosphorus, numerous ferries do their bit. The Bosphorus leads North to the Black Sea and South to the Marmara Sea and via the Dardanelles to the Aegean and Mediterranean Sea. The European part of the city is divided in two parts by the Golden Horn, the towns historical port and smaller waterway, its only outlet is the Bosphorus.