Kent forest located on the Anatolian side in Beykoz https://goo.gl/maps/CNGUaftzbTU2Is in a very easy and reachable location where you can hike to it from Beykoz right after leaving Bus number B15 it is only 20 mins walking distance from the bus stop. The forest used to have a dim that’s now dried and apparently being projected for a certain type of sport.
The approximate walking distance there is about 2 hours, no hard terrain but the ground where you can walk on is not sand but rather stony.