Hampstead Heath is the place to go if you fancy a taste of the countryside in Zone 2. The perfect park for kids and dogs alike, or really anyone or anything that likes to squelch about in the mud.
Visit Parliament Hill Fields for its great views of Central London as you can see for miles on a clear day. The Parliament Hill area also includes an athletics track and a recently refurbished playground with an accessible swing and a paddling pool, if you or your kids are not quite ready to brave the bathing ponds and an accessible swing.
The Hampstead Heath bathing ponds are also a big draw to the park. Younger kids and not-so-confident swimmers should probably stick to a normal swimming pool as the water is very deep. The best but also busiest time to visit the ponds is the height of summer.
Kenwood House and Gardens can also be found in Hampstead Heath. As can Golders Hill Park which has a small zoo and a butterfly house in summer.