In the era of Ottomans it was the outer garden of Topkapı Palace. After it restored as a park and opened to public. There is no entry fee to the park, however the museums inside are not free. There are thousands of tulips and hundreds of other plants are living in the park in a harmony. There are touristic horse carriages that can give you a ride around the park in an authentic way. On weekends with nice weather, the place can be a little crowded. But a must visit park in Istanbul for sure!