Free to visit, both day and night, and the nighttime lighting is beautiful.
Although Belgrade is relatively safe, it's recommended to arrive early and leave early in the evening. I went before 10 PM on a Monday, and there were still quite a few people. Instead of walking along the river, I exited the park northeast and entered the old city's food and beverage district, which was safer.
[Scenery] Good
[Entertainment] Good
[Value for Money] Good