Checked out Košutnjak... a hill to the west of the city. It wasn't as far as I thought it would be. Pretty dense, lots of paths, a few runners, dirt trails. Fun! Could be a go-to running route. It's a lot of lights and crossings to get there, but once I'm there... it's just wandering around a forest...... ah scratch that - it IS far. We didn't even make it to Košutnjak! We were just barely near the beginning of it!