Athens is short on playgrounds, but between ice cream and street musicians and stray cats, there's plenty to keep kids amused. It helps too that children are welcome everywhere, and at casual restaurants they're often encouraged to run off and play together while the adults eat.
Parks and Gardens
The shady National Gardens has a playground, duck pond and small (if somewhat dismal) zoo; immediately south, Zappeio Gardens also has an enclosed, shaded playground.
Attica Zoological Park has an expanding collection of big cats, birds, reptiles and other animals, including a monkey forest and 'Cheetahland'. It's near the airport. And when all else fails, Allou Fun Park & Kidom has thrill rides.
Museums and Spectacles
The Museum of Greek Children’s Art has a room set aside where children can learn about Ancient Greece. The Hellenic Children's Museum is a good place to meet Greek kids. Older children may like the War Museum, where they can climb into the cockpit of a WWII plane and other aircraft.
Escape the heat and amuse the kids with a virtual-reality tour of Ancient Greece at the Hellenic Cosmos (call ahead to arrange English translation), or explore the universe at the impressive Planetarium.
Cinema and Theatre
Younger children may enjoy Greece's traditional shadow-puppet tradition. Shows are in Greek, but slapstick, with lots of music. In summer, visit Theatro Skion Tasou Konsta; in winter, check the Melina Merkouri Cultural Centre and Figoures & Koukles.
An outdoor cinema makes even a Hollywood blockbuster special. Only films for the youngest kids are dubbed; everything else gets Greek subtitles. These open roughly May through October around the city; check www.athinorama.gr (in Greek) for schedules.