For days it was planned, then executed with precision. Sand bags, tarpaulin, a few wooden pallets. I watched from the window as the den took shape, not realising that soon it would become more important than we could've imagined.
While it was built (with the help of their dad) in the days pre-lockdown, the 'bunker' as it's become known, has become a refuge. An old carpet was repurposed as a soft floor. A couple of cushions that have seen better days made it more habitable. The tarpaulin acts as a rain cover. Their favourite sticks have homes in between the pallets. Worlds are being created outdoors where the wild things are.
My two boys are spending a lot of time in their den at the back of the garden. No school and no after-school activities means like every other family in the country we are not leaving home except for a walk. The mad dashing around and shuttling-here-and-there treadmill that we were on has stopped abruptly.
The fine weather has meant lots of time outdoors for all of us; walking the dog and exploring our own local area within the 2km limits imposed. Lockdown has meant trying to find new ways of looking at the world - getting closer to nature by being outdoors may be one of the few upsides.
In his bestselling book, Last Child in the Woods, Richard Louv writes that never before in history have children been so plugged-in - and so out of touch with the natural world. He identified what he calls nature deficit in today's wired generation linking it to some of the most disturbing childhood trends such as rises in obesity, depression and Attention Deficit Disorder (ADD).
In his follow-up book Vitamin N, he argues that time outside is even more essential for both children and adults, pointing out that "nature experience is resting the brain from the burnout of looking at screens all the time".
He also suggests that by immersing yourself in nature right now - even if that is to sit by a tree, observing the comings and goings of the birds and getting to know these things as if they were your relatives - that you can reduce your own sense of isolation.
The longer evenings and the fact that we have literally nowhere to go means that this spring is the perfect opportunity to connect with nature, according to wildlife expert Paddy Madden.
At his home in Co Kildare, he's busy in the garden cocooning with his wife Kay. As one of the Heritage Council's schools experts, Paddy goes into schools to spend a day with primary school children passing on some of what he's learned over the years.
And while he says not everyone will have access to a large garden or outdoor space in lockdown, you don't need these things. What's important is that children get outside for times of unstructured play in nature when they can create worlds with sticks, stones and branches.
Now is the perfect time to plant a few simple annuals like cornflower of Californian poppy, he says. Planting these sweet-smelling flowers will encourage pollinators into the garden. Not having your garden or planted space too manicured and leaving room for a few wild flowers like the dandelion will also bring in the bees and butterflies, he suggests.
Through his work, Paddy knows children love to grow things. By cutting a milk carton in half and putting a few scallion seeds or even marrowfat peas in soil, they can watch the progress of the young plants sprouting. These can be placed on window sills if space is tight.
Another activity he likes to encourage is bug hunting. All you need is a paint brush, a jar and a spoon. A magnifying glass is also useful but not essential. Children can get busy looking for what he calls these "mini beasts" by checking under logs or stones to see what they can discover.
"When you lift these, brush the creature on to the spoon and put it in the jar. You could bring a bit of competitiveness into it as well by seeing who can find the greatest variety of creatures like wood lice, snails, slugs, ladybirds and spiders," says Paddy.
Another activity he likes is to stop and listen to the different sounds. "You can really hear the birds singing at this time of year. You don't have to have a huge amount of space to do this. Birds are singing everywhere. One of the best gifts you could give a child is a pair of binoculars. It's like magic - then they can see the black bird calling to the female," he says.
Family walks present great opportunities to engage with nature, he says. Even if you don't know the name of a plant or animal, you can identify it later online.
When he was setting up his new website, which has a host of activities for parents and children, he recalls looking at plants in a ditch on a roadside near his home. A woman passed by and asked what he was doing. He pointed out some of the green vegetation and their names. She said she had been walking the same road for 30 years and had never even noticed. Having your eyes open to nature is the key, he says.
Paddy advises to do things simply by identifying something new in nature every day. "Today it might be a wood pigeon, tomorrow it could be a primrose. Encourage children to use all their senses to see, smell, touch and hear something new every day. That's how I got to love nature learning about it through all my senses".
Outdoors experts and husband and wife team Dan Westall and Naomi Walmsley run forest courses for children at their home in Shropshire in the UK. In these abnormal times, they believe parents and children alike are embracing the outdoors and making the most of the time they have together.
Engaging with nature doesn't just mean exploring rural spaces, their new book Urban Forest School, the follow-up to their book Forest School Adventure, provides lots of ways for kids to engage with nature wherever they are.
"You don't need access to the words to have an experience in nature. Nature has been titled as the woods or a park but everything is nature. People don't always have gardens but that doesn't mean you can't grow something in a pot. Step outside the door, go for a night walk - you'll potentially see a bat or a fox. Build a sheet den outdoors," says Dan.
He argues that parents are role models for their children. By slowing down and looking at things, we are already teaching them to do the same, he says.
Simple things, coring an apple, putting butter and seeds in it or cutting an orange in half, eating the fruit and filing it with seeds and peanut butter, provide excellent bird feeders that can be hung up.
Their books have lots of activities for kids from botanical interactive art to making goblin villages or mini dens, one of Naomi's favourites.
She suggests buying some air-dried clay to make the figures and then picking up a few things on your walk like sticks or stones which can be used to construct the mini den. The goblins or trolls who inhabit these can be dressed by finding a snail shell to use as a hat or a bit of ivy for a jacket.
Another activity they suggest is to do a simple "sit spot" at your front door where you observe everything. "The whole premise is that you don't really move - you just sit and listen to the sounds," says Naomi.
By opening the world to nature for your children, they believe that you're creating a chance for them to explore, use their imaginations, build their self-esteem and improve their health.
For more information see Paddy Madden's website engagewithnature.ie. Forest School Adventure is available at bookshops and Urban Forest School will be published this summer