One of the green oasis of Northern Suburbs of Athens is undoubtly the Alsos of Veikou (Veikou Park) of Galatsi.
There are Sports facilities such as Football field, Basketball Arena, Tennis courts,swimming pool etc, and an open air Gym where you can practice for free!
If you want to just stroll around there are beautifull paths around the park where you can walk for hours!
And then when you meet one of the 2 centrally located cafes, just sit and relax with a cafe under the trees.. away of the crowded city! Otherwise one of the kiosks provided is a good solution!
For the kids there are beautiful playgrounds on top of the grass.
You can access Galatsi’s park with public buses.