Kemerburgaz Urban Forest (Kemerburgaz Kent Ormanı) is a new and wonderful recent addition to the running scene in Istanbul. This large open space, located a 20-minute drive from central Istanbul, is a large green space with many km of walking & cycling paths, numerous sports fields, and other facilities such as cafes and playgrounds. The landscape is a combination of open and wooded terrain. There’s a lake and old aqueduct at the northern end. Pro Tip: Great option on a hot day — shaded and away from the city! 

For running, your best bet is to do one of the three designated, marked walking/running trails, as shown in the park map. There are trails of 3.4 km, 5 km, and 10 km. Half of the 10k Purple Trail overlaps with the 5k Blue Trail. The 3.4k Green Trail is at the northern end of the park, near the lake.