In short, the pastime involves looking for a container, the geocache, that has been hidden by another avid treasure seeker. This container holds a log book and the coordinates of the cache are posted on a website, enabling it to be found using a global positioning system or GPS receiver.  “It sounds more complicated than it actually is. It’s not rocket science – I’m certainly not the most technical man in the world – and Daisy does all the computer stuff,” Phil says. Geocache expeditions range from 'difficult hikes’ with more cryptic clues, which can often be cleverly camouflaged in woodland or mountainous terrain, to an 'easy adventure’ in an urban or rural setting.  Rocket science or not, we can thank the US military for the satellites that enable a GPS receiver to work. Originally used by the American Defence Department, the system was handed over for unrestricted civil use in 2000. It is now an integral part of our lives and features in everything from satnavs to mobile phones.  The cache that we are looking for today is known as a multi-cache and takes the form of a treasure hunt.  “By logging onto a specific geocache website and entering your postcode you can find caches near you,” Phil says. “This one is called the Southwell Heritage Trail and has been designed to take you around the town finding clues. The answers to these clues are then used to decipher the coordinates to the location of the final cache.”  So far it has taken us to the football club, across the grounds of the imposing Southwell Minster, to the pub where Charles I stayed and on our way to a house once owned by Lord Byron.  This cache was created by Barbara Hastings, 56, and her partner Steve Moses, 59. They have been avid ''cachers’’ for four years.  “Since we started we’ve found 646 caches in 10 countries,” Barbara says. “We also own 61 caches, so we make sure that they are maintained and field questions from people who are trying to find them.”  The craze looks set to grow. It is estimated that there are more than a million active caches all over the world – and five million geocachers hunting for them – from Hong Kong to Norway to Greece. Entering my postcode into the website there were 10 within a mile of my house. Give it a try, you’ll be amazed.  That most venerable of institutions, the National Trust, also has events at its properties throughout the UK.  “They can be stashed anywhere. Deep in the countryside, along rivers, national parks and cities,” she says. The geocaching community has also set up an environmental initiative, Cache In Trash Out, to encourage hunters to pick up rubbish spotted along their trails.  “The location and clues are only limited by the ingenuity of the people who set them up,” Barbara says. “And they can be very, very ingenious.”  With all the clues solved, the flashing arrow on Daisy’s receiver is now pointing us to the final cache.  “Found it!” As her voice rings out, we see that she’s holding a small black plastic box that she’s fished from the undergrowth. Excited fingers grapple with the lid and we all gather around to see what’s inside. There’s a toy car, some crayons and a little book that has been signed by previous cachers. We swap the car for a plastic whistle and scribble our monikers in the book.  “That was great, Dad,” Daisy says. “Can we do another one when we get home? Or how about we set our own cache up? I’ll think of the clues and we can make it really difficult.”  As her chatter fills the early evening air you wouldn’t have thought that she’s been out walking for the best part of two hours. What’s more, neither does she. Now, there’s a great distraction for the children at half term.  First log onto the website www.geocaching.com and enter your postcode. This will give you all of the caches in your area.  Pick one that takes your fancy by looking at its description and comments left by previous users. Log in by creating a user name and password. Print off the sheet with the cache coordinates and clues.  Load these into your GPS receiver and you are ready to go.  A good GPS receiver doesn’t need to cost a fortune. Garmin Geko 201, £70, is a small hand-held device that is easy to use and very robust.  Garmin Etrex X, £70 – 17 hours of operation from two AA batteries make this a very efficient piece of kit.  Magellan Triton 1500, £170 – touch-screen technology that is rugged and waterproof.  Hide the Xbox and get the family out and about for the day at a number of National Trust events throughout the country. There are seashore safaris and castle quests, scarecrow making and forest art, bug hunts and cookery classes from Cornwall to North Yorkshire. For more information: www.nationaltrust.org.uk/events.  Grate, crush, pound, pestle and stir spices at an interactive workshop aimed at children from five to 11, which will immerse them in the smells and flavours of Indian cuisine. The chefs at the Cinnamon Kitchen, London W1, will show them how to use spices including tamarind, liquorice, cardamom, anise, saffron and ginger to great effect, making child-friendly canapés and Indian snacks to add to the family repertoire.  The classes run from February 21, £25 per child for under 11s. For more information: 020 7626 5000; www.cinnamon-kitchen.com.  The Premier Dance Studio offers a half-term dance workshop for all ages. Give hip-hop, disco or lyrical dance a whirl or dancercise the day away. February 21-25; 10am-4pm; Yateley, Hampshire; £18 admission. For more information: www.danceweb.co.uk.  Be entertained by All the King’s Fools at Hampton Court Palace, Surrey. The Misfits theatre company is staging a promenade performance at half-term. Learn how to stand, dance and play music like the Tudors. From February 24-27; 10am-4pm; £14 adults, £7 children. Call 0844 482 7777 to book tickets.  Take a tea party with the dinosaurs at The O2, East London, from February 18. Billed as the largest animatronic dinosaur adventure in Britain, the event has more than 22 life-size dinosaurs, interactive displays, a prehistoric aquarium and presentations by wildlife expert Chris Packham. Ideal for budding palaeontologists from ages two to 12. It costs £42 for a family ticket (two adults, two children); £14.20 for an adult single ticket; £11.25 for children.  To book tickets, visit: www.dinosaursunleashed.co.uk
Geocaching is a great way to get outdoors and learn about the local area, says Gary    King