I cycled to Volkspark for the first time this weekend, and while a lot of the park is relatively…read moreuncared for, there is some great woodland and nice paths for walking, jogging or cycling. I should mention that it's not suitable for roadbikes - a mountain bike would be best. The woodland here was actually more fun to cycle around than that in the nearby Niendorfer Gehege forest, and there are some reasonably sized hills.
Almost part of the park is the Dahliengarten which is incredibly well cared for, and I assume from walking around it has probably the biggest collection of Dahlia flower species in the world. Also just on the edge of the park is the Hauptfriedhof Altona (main Altona cemetery), which is also nice to walk around.
Overall, I think it's a better park for cycling, jogging or walking the dog than actually using as a standard park - most of Volkspark is forested.