If you're off to London with the family, you want to know what activities and sights will keep everyone happy all day. And you don't want to be spending money on entrance fees for every member of the family, on top of food and accomodation.
So we've gone beyond the usual suggestions of the Science Museum and Hyde Park to find some of the capital's lesser-known gems that are family friendly and don't cost a penny.
See a new side to the city with a free guided walk
Walking around a city with as rich a history as London is infinitely more enjoyable with a knowledgeable guide. Inmidtown offers just that, with over 100 routes presided over by London expert Aly Mir - and all for free. You can see what walks are coming up soon on their website.
If you know all there is to know about the city's top picture-postcard attractions, a themed walk can take you deeper. Charities or local history clubs frequently run tours exploring specific topics in London's colourful past, like crime, music and the role of women. Keep an eye out for these!
WalkLondon, funded by Transport for London, contains details of seven specially-developed walking routes designed to show off sides of the capital that might otherwise go overlooked, such as the Lea Valley and the Thames Barrier. The tours are self-guided, but most of the routes are well signed.
Camden Lock Market
Camden is London at it's frenetic best, and nothing demonstrates that better than the market, which runs all week around the area's famous canal.
Older children and teenagers will revel in the cool clothes stalls and grungey vibe, which has managed to survive the neighbourhood's transformation into a tourist mecca, while younger ones will be fascinated by the life and colour all around.
And if it's all getting a bit much, you can grab a drink and a bite to eat down by the water and watch the canal boats chugging by.
It's child heaven! Playgrounds, sandpits, sports pitches and a city farm, right in the heart of central London. And it doesn't cost a penny to use!
Surely it's too good to be true? No, that's exactly what Coram's Fields is. Set in seven acres of grassy parkland near the British Museum, the centre is a safe, fun and wallet-friendly haven in the heart of the city.
Although the facilities are free to use, Coram's Fields is a charitable organisation - so if you can, do make a donation to maintain this invaluable resource for locals and visitors alike.
You'll need a strong stomach to handle parts this museum of medical oddities, but kids will probably revel in the more gruesome exhibits.
Named after surgeon and anatomist (are you getting the idea, yet?) John Hunter, the Hunterian Museum is part of the Royal College of Surgeons and houses delights such as antique surgical instruments, jars of preserved organs and a vast collection of human skulls. Lovely.
Not only does Hampstead Heath provide some of the most spectacular views of central London you're likely to find, there's always plenty on for families - most of it completely free.
The famous swimming ponds are not suitable for children under eight or weak swimmers, but the boating pond, adventure playgrounds and paddling pool mean that children of all ages will be entertained while you enjoy the tranquility of one of London's most beautiful spots.