After being warned that the Acropolis is boring for young children, we decided to spend our morning in Athens in the National Gardens and let the two 3yo kids we traveled with be kids. At first, The National Gardens look like a maze, especially as the signage is really poor. Even with the maps, it's hard to be sure if you're going the right way. Overall it looks old, poor up-keep and uneven pavement, but for its purpose it's grand! The playground were shaded, varied and well equipped: toilets in the corner (with and without doors), drinking fountain, and a decent number of swings, climbing bars, sand-pit, mini-houses and slides.
In the gardens themselves, there are a lot of nooks and hidden treasures, like a turtle pond, small bridge, rose avenue, mini bird zoo, and the like.
It's not ideal, as it feels old. But if you want a place where you can let the kids run a bit, and you like 'treasure hunts', it's not a bad way to spend a hot morning in Athens.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.