Sim on the terrace of the Sakip Sabanci Museum.  Yesterday we took a long walk north on the Bosphorous to this museum. (Longer than I intended.  I estimated 30 minutes based on the map.  It took more like an hour and ten.  But it was a beautiful day.)  The museum is in a mansion and has an exhibit on the history of Istanbul.  We took the bus back and had a nice balik (fish) dinner waterside.  Great sea bass.