Start by taking tram 22 from the centre of town up to Prague Castle – the route takes in some of the city's prettiest streets before dropping you near the top of the hill. The castle, the world's biggest, is great for kids of all ages. Arrive a few minutes before the hour for the hourly changing of the entrance guard – a choreographed confection straight out of Chitty Chitty Bang Bang. Within the castle walls, vaulted Vladislav Hall is sure to fire up a child's imagination: it has a sweeping staircase down which mounted knights used to enter. The castle is also home to the old-fashioned Toy Museum, with a mammoth collection of everything from tin soldiers to china dolls, none of which you can touch.
Wend your way downhill through pretty gardens to the famous Charles Bridge. A good diversion here is guessing the identities of the 30 parapet statues (try to find the one of St Wenceslas as a boy with his grandmother). The bridge is invariably thronged by wannabe artists, and a two-minute portrait or caricature makes for a fun family memento.
On the far bank, Old Town Square is Prague’s architectural highlight. Guidebooks make a big deal of the astronomical clock, with its mechanical figurines who parade hourly. But – whisper it quietly – it's all a bit dull. It’s much better just to wander the surrounding streets – the whole district is as pretty as a film set, which is what it often becomes. Find out from the tourist office if there's anything currently on location and wander over to have a look – older children and teenagers will love the Hollywood bustle and seeing the behind-the-scenes secrets of how a film gets shot.
When you're done with the sightseeing, it's just a few steps to the outrageously decadent Obecni Dom, a wildly over-the-top temple of Art Nouveau housing the city hall. The ground-floor houses a grand palm-court café serving afternoon teas with huge ceremony but fair prices.
Finish the day with an hour's cruise (or longer) on the River Vltava, watching the city-centre sights pass by from a different angle. If that’s too easy, you can burn off a few calories by hiring a rowing boat from the docks opposite the National Theatre on Slovansky Island.
When it comes to letting off steam, small children enjoy the well-kept playground on Kampa Island, two minutes’ walk from Charles Bridge. For bigger kids, the top choice is Petrin Hill: you can zip up on a dinky funicular, and at the top you'll find, aside greenery, an old-fashioned mirror maze and pint-size Eiffel Tower (giving the city's best views).
Further from the centre is Prague Zoo, one of Europe’s best. Its reputation rests on its breeding herd of wild Przewalski’s horses, but children of all ages enjoy spotting their favourite animals in well-tended, spacious enclosures. Younger kids also love hands-on contact with smaller animals in the petting zoo set around a traditional farmyard.
If it rains, Prague has some diverting – or just plain kooky – museums to ward off boredom. Outside the centre, trains, planes and automobiles fill the Boys Own zone that is the National Technical Museum, which also has a coal-mine in the basement. But the award for oddball excellence must go to the Museum of Miniatures, full of objects you never knew you needed to see – and therefore of huge interest to children: a grasshopper playing a violin, a flea wearing shoes and a whole camel train passing through the eye of a needle (don’t worry, there are a lot of magnifying glasses as well).
For day-trips from Prague, see our Central Bohemia destination guide.