Mud pies, meandering streams, puddles or dusty pathways and long grasses; the slime of frog spawn, dens, tree houses, caves or the simplest shelter at the heart of a bush; for most adults all these things and a hundred others were the stuff of our childhoods.
But when the National Trust brought out its Natural Childhood report in 2012, it looked at the way our own children are living and revealed a worrying picture of a generation that are growing up indoors and disconnected from the natural world. Examining recent research, it detailed that only one in three children can identify a magpie, while nine out of ten could pick out a Dalek. British children were watching more than 17 hours of TV per week and spending 20 hours per week and more on social networks.
What was causing this? The report looked at a number of causes, such as parental anxieties about traffic and "stranger danger", and found that nearly half the parents who participated believed that the earliest age at which a child should be allowed out alone was 14. One boy, whose great-grandfather had regularly set off as an eight-year-old to walk six miles to his favourite spot for fishing, was taken to school and back in the car and restricted to just 300 yards around his house.
But what does this mean for our kids? As Richard Louv writes in Last Child in the Woods, "For a new generation, nature is more abstraction than reality. Increasingly, nature is something to watch, to consume, to wear – to ignore". And yet, scientists are increasingly uncovering the vital benefits of outdoor life, of which reduced stress, greater psychological resilience, and a lower chance of obesity are just a few.
To which end, this summer the National Trust has created 50 Things to Do Before You're 11 ¾. With help from kids around the country, they've compiled a list of all those wonderful things that every child should be able to experience – from cooking over a campfire, through tracking wild animals to building a den and climbing trees. Other challenges include riding bike trails, hunting for fossils and bones, birdwatching, jumping into the sea, or simply setting out for a barefoot walk and letting the warm soil tickle your toes.
What would the world be, once bereft
Of wet and of wildness? Let them be left,
O let them be left, wildness and wet;
Long live the weeds and the wilderness yet.
Gerard Manley Hopkins
Simply sign up for free at nationaltrust.org.uk/50things for top tips, secret adventures and your very own virtual explorer who will guide you as you complete each activity. The only question now is whether you and yours are up to the challenge!

Want to know more about why we all need wild time? Well, the 50 things to do before you're 11¾ Wild-time Challenge and the National Trust are supporting film-maker David Bond who, like many parents (and grandparents) is concerned. He can't persuade his kids to go outside. His feature-length documentary Project Wild Thing follows his journey as he appoints himself Marketing Director for Nature, to try and get his and other British kids to enjoy nature.
His product is free, plentiful and has proven benefits – but can he convince his family (and the UK) of this?
Look out in October for David's heartwarming, hilarious and thought-provoking film Project Wild Thing and help us connect kids with nature. Watch the trailer and find out more.