It is easy to miss as not much is made of it in tourist literature and it is reached either by a lane (which has attractive wooden houses and the splendid Sarnic cistern restaurant) in between Hagia Sophia and the Topkapi Palace or at the north end of Alemdar Cad. There is also a 'Gulhane' tram stop a short way north of the entrance.
This is a wonderful park: with views of the Golden Horn and Bosphorus on one side and the wall of the Topkapi Palace (interesting to view this sight from below) on the other. It is beautifully planted and very well provided with benches and various quirky and attractive features. Be warned, though, that the toilets cost a Lira and are of the dreaded 'Turkish' type. At the far end of the Park is a cafe Set Ustu Cay Brahces with superb views over the water. Unfortunately the range of drinks is very limited - I couldn't get an orange or a lemonade and certainly didn't want a Fanta, so we had a pot of tea for two at 14 Lira. But it's a great place to just sit and look out over the Bosphorus as a mid-point in a circuit of the park.