In February, we were with a group of tourists from Gelendzhik in the park next to the Chamlydzha mosque, a very beautiful, well-kept area. It offers a magnificent view of Istanbul. There are gazebos. Be sure to take a walk in the park. We Are Thrilled.
A beautiful city park, very large uphill, but the view from it is beautiful on the city and the bay. Take water with you, there is a cafe on site, there are benches too, you can sit in the shade of the trees. The height difference is very good, but it's worth it, who does not like to climb mountains or with a stroller, I do not advise, only at the foot of the mountain you can sit, it will be hard to climb.
It's a cool park around the TV tower, but like many things in Istanbul, it's on a steep slope. Definitely worth a visit. There is an observation deck and a dining room upstairs.