If you are the type of the person who likes to visit the historical places and palaces, so Istanbul is the perfect choice. There are lots and lots of sightseeing places that worth visiting such as: Hagia Sophia, Blue Mosque, Grand Bazaar, Topkapi palace, and the ancient Ephesus and the house of Virgin Mary. Concerning the weather of Istanbul at summer, it is a moderate fine weather. It is not that totally cold nor that hot.