If you are visiting Palais Longchamp, it's worth walking up the steps if you're able to check out…read morethe Parc Longchamp. Opened in 1869 same as the palais, it's a nice English style landscape garden to take a walk around. One thing I learned after the fact, was within this lovely park is a 150-year-old plane tree and an oak and a Siberian elm that are both 120 years old. Antique nature.
When we were walking around, there were others sitting alone reading and a large group playing frisbee together. This may be a small park, but it still has a lot of life in it. They had a map, some statues, and remnants of an old zoo. Some cages still stand from the 1987 closing - it's actually quite fascinating to take a look through. The zoo was closed when the public decided keeping animals in cages was no longer a good look. Good for them.
It's free, same as the Palais and usually open until sunset.