The Oran Forest is a great spot to quickly get out of the city and breathe some fresh air and enjoy some trees and hiking. The forest is owned by METU (Middle East Technical University) but half of the park is open to the public. The forest is extensive. When you first enter, you will be immersed in a managed pine tree forest and as you walk furthur in you will find yourself on a ridge overlooking a lake and a natural landscape.
To get to the forest, take a dolmus from Kizilay to Oran. The ride will take you approximately 30 minutes. If you ask the driver where the forest is, he will drop you in the right place (Nerede orman?). If trying your Turkish is too intimidating, watch for the trees to appear on your left hand side---do not get off until about 5 mintues of trees have passed you by. Most handy is the sign for Panora on your right hand side (a large mall in the area). When you see the sign for Panora and the dolmus subsquently turns right, get off and walk towards the trees. There are multiple entrances to the forest and plenty of room for exploration. Enjoy!