After travelers visit London's must-see main attractions like Big Ben and Buckingham Palace, there are hidden treasures for families to find that are budget-friendly and, because they are off the beaten path, often less crowded and touristy. 

 1. Ferry and Day Out in Greenwich - More than just the Prime Meridian, Greenwich has enough for a full day to entertain parents and kids of all ages. Take the public ferry through London to see great views from the Thames all the way east. Enjoy a visit aboard the Cutty Sark, visit the free Maritime Museum and Royal Observatory. Bring along a picnic for gorgeous views in the expansive park overlooking the city and broad hillsides for your children to run and play.

2. Royal Air Force (RAF) Museum - Adults and kids love seeing aircraft up close and, while this museum is a bit outside the city center, it is free and easily accessible by Tube. Wide-eyed children will enjoy the hundreds of historic crafts spread throughout the spacious museum.

3. Imperial War Museum - Another of London's excellent free museums doesn't see the crowds that the British or Natural History might boast, but that is a plus for families looking to escape the crowds. Hidden behind the South Bank and having undergone a recent makeover, this museum is packed full of interesting exhibits and provides kids an acitivity book to follow along as they go. 

4. Sky Garden - If you are looking for great views over the city, but don't want to pay the high prices of other skyscrapers, book a free reservation for the Sky Garden. Located in the new "Walkie Talkie" building in the Financial district, the lovely garden-scaped rooftop offers incomparable views that will leave you breathless.

5. Free Family Walking Tours - For a great local's peek into London neighborhoods, join one of the many free walking tours offered at Free Tours by Foot. Learn about the cluster of family-favorite museums and playgrounds on the West Kensington Family walking tour, or explore the unique food offerings in Soho on a historic food tour. Each experienced guide provides 2-3 hours of learning and you only pay what you feel it was worth at the conclusion.