Very nice and well maintained park. A lot of large open green space, some statues, London ZOO is part of it. Entrance to park is free, ZOO has an entrance fee. A great place for walking or running, if you are into it. A lot of opportunities to just sit on the bench or lawn and relax. There a also a few places offering coffee, refreshments and some small bites.
Especially on weekends you will find a lot of people having picnics, families with kids. Dog friendly place.
Adjacent to it is Regent canal- another opportunity for walking and running.