City breaks with kids: London

London offers a dazzling parade of attractions and treats for children – but it can empty your pockets faster than Fagin. Here are our tips for making the most of the city on a budgetMore in this series: Paris | Barcelona | Amsterdam | Berlin | RomeSome of London’s most popular attractions are also its most expensive – looking at you Madame Tussauds (from £107 for a family of four), London Zoo (£84.60), London Sealife Aquarium (£136). On the plus side, most ma