It is in Göztepe (Asian Side), owned by Sunay Akin, who is a enlightened Turkish author and poet. He collected many toys from history. Also the football signed by PELE exists here. The museum is a mansion, and very clean. I suggest you to visit WC (Basement) which is like Submarine:)
Hagia Sophia built in 537. It was a former church and converted to mosque when Istanbul taken over by Ottomans. The dome is accepted to be one of the largest dome and it's still a big questionmark that “How such a big dome can be built in that age”
It is built in 1491 and it is the first Mevlevi Lodge of Istanbul. You can see many mevlevi items here. Mevlana Rumi is the creator Mevlevi belief. It is based on divine love, humanity and endurance. You can also watch Whirling Dervish Shows here. Shows are time scheduled and paid seperately, so you can check before making your plans.
It is located in Ibrahim Pasha Palace (Ibrahim Pasha is Grand Vizier of Sultan Suleyman and he married with Sultan Suleyman's sister). Museum founded in 1913. Museum has the biggest Islamic Art Collections (Such as Promet Muhammed's personal belongins, food prints and beards). Also many items of old Turkish countries are presented here as well (Such as 800 year old carpets, karlowitz treaty which caused the first land loss for Ottoman Emprire)
Miniaturk is a very big open air museu which includes small models of many Turkish architecture both in Turkey and abroad. Also you can read their history. Its great for shortening Turkey tour to couple of hours:) It has a nice chopper simulator as well.
Cistern Basilica was built in 6th century by Roman Emperor Justinian in order to provide water for the city. This cistern is an underground chamber of 143 meter by 65 meter. The ceiling, which covers 9800 m2, is being carried by 336 marble columns each 9 meter high. The capitals of the columns are mainly Ionic and Corinthian styles.
It is Istanbul's first maritime museum which founded in 1897. If you like ships and sea wars, you will like this museum too. It has cannons in the gardon. Small ships inside. Also the oldest galley is presented in this museum.