The presenters look back at some of the amazing dens from series one and two. Here, Lauren revisits the survival, art, Hollywood cinema and DJ dens.

The presenters look back at some of the amazing dens from series one and two. Here, Lauren revisits the train, magical library, community and plane dens.

Helena needs a den to help her reach for the stars and fulfil her science dreams.

Will needs a rugby den to keep him in the game.

Joe and Lauren help build a den for the children and their siblings at Claire House Children's Hospice in Liverpool.

Ocean loves marble runs because they're like rollercoasters and one day he'd like to be a rollercoaster designer. He wants a marble run den.

Astrid needs a Christmas den so she can enjoy that special day all year round.

Brothers Alec and William want a den that looks like a traditional Scottish castle.

Nine-year-old Nya really needs her own space to indulge her love of martial arts.

Ten-year-old Dilara wants a Turkish den where she can share her passion for Turkey with her friends.

Nine-year-old Kiran wants somewhere he can let his love of witchcraft and wizardry come to life.

Eleven-year-old Cammy, who is one of six siblings, needs a place where he can be on his own, in calm and quiet.

Nine-year-old Maddie needs a space of her own where she can focus on her sporty future.

Joe and Lauren look back at all the amazing dens built throughout the series. They reminisce about the great kids, the tense surprises, and the big reveals.

Eight-year-old Oscar lives in Scotland and wants an Australia den so he can remember his Aussie hometown.

Eleven-year-old Amelie wants a Queen Victoria den where she can pass on her love of history to her friends.

Eleven-year-old Yusuf dreams of being in the army and hopes to one day to use his love of computer coding to become an army intelligence officer.

Cara, who has a form of dwarfism, has a sweet tooth and loves to dance. She needs a Sweetie Den where everything is the right height for her and she can disco dance!

Jilan, 12, has a passion for politics and wants to be prime minister one day. She needs a Politics Den where she can plan her campaigns in peace and quiet!

Rhodri can't go to his local cricket club as often as he'd like. Rhodri needs a den where he can practice cricket whenever he likes.

Daisy loves sewing but has to pack everything away when it is dinner time. She needs a sewing den where she can create fabulous designs in peace.

Archie needs a farm den where he can grow and harvest vegetables and look after his chickens.

Tali needs a magic den where she can practise her tricks in secret, without giving the game away.

Campbell needs a cycling den where he can cycle all over the world without getting oil on his parents' sofa.

The Dengineers help St Hugh of Lincoln Primary School in Manchester create a new space for pupils with specific needs from an old double decker bus.

The presenters look back at all the amazing dens the team have built throughout the series and reminisce about the great kids, the tense surprises and the big reveals.

Lauren and Joe revisit the eco, Scottish castle, Turkish and sport dens.

Lauren and Joe revisit the observatory, gingerbread house, sensory and community dens.

Twelve-year-old Luke is passionate about black history and wants people to realise how important it is.

Ten-year-old Caitlin wants to become a conservationist when she's older. She is passionate about teaching other people how important our world is, and needs a den where she can research.

11-year-old Maariya was scared of going underwater but overcame her fear a few years ago. Now she loves swimming, snorkelling and all things underwater.

Eight-year-old Nathan loves learning all about the rainforest from his dad and wants a den so he can feel like he is deep in the Amazonian rainforest every day.

Becca and her twin brother, Charlie, loved their new chinchillas. However, one of them was pregnant and gave birth and the only way to save them from being rehomed is to have a chinchilla den.

Twelve-year-old Ashley needs an opera-themed den so he can sing to his heart's content. He has Tourette syndrome and singing helps him to overcome it.

Eight-year-old Mei is half Japanese and loves learning more about Japan's culture. She doesn't get to visit as often as she would like so needs a den where she can celebrate her Japanese heritage.

Nine-year-old Jothi had an illness as a baby that caused his legs to not grow properly, meaning he can't visit his favourite crazy golf course. Jothi needs a crazy golf den he can access all the time.

11-year-old Holly has chronic actinic dermatitis, eczema caused by UV light, and needs a calm and relaxing den to help forget about it.

Ten-year-old Evie wants a den where she can spend quality time with her aunt, whose chronic rheumatoid arthritis means she is unable to get up the stairs to Evie’s room.

Eight-year-old Matthew needs a den so he can teach his sister the board games he has grown to love.

Ten-year-old twins Becca and Lottie need a den so they can enjoy wildlife and bugs together. Becca has cerebral palsy and her wheelchair makes it difficult to play in the garden with her sister.

Joe and Meryl look back at all the amazing dens built throughout the series and reminisce about the great kids, the tense surprises and the big reveals.

Joe and Meryl look back at some of the amazing dens from this series and catch up with our Dengineers to see how the dens have changed their lives.

Joe revisits the Queen Victoria, Australia, Sewing and Army Coding Dens.

Ten-year-old Florence from Oxfordshire wants a cool hotel den so that she can relax, hang out with friends and be on holiday whenever she wants.

Doctor Who fan Adam wants a den where he can celebrate his favourite TV show and pursue his passion for drama.

Vilonu is a huge CBBC fan and dreams of becoming a TV presenter when she is older. She wants a space where she can write, film and edit her very own TV shows.

Gregor from Aberdeenshire needs somewhere to practise, store and maintain his bagpipes. He dreams of becoming a professional, but his pipes are too loud for the rest of the family.

Amayah from Sheffield is a huge fan of the weather and dreams of becoming a forecaster. She wants a den where she can study the weather and create her very own forecasts.

Ciarän from Barnsley is passionate about engineering and vacuum cleaners. He wants a den where he can create his own inventions, understand how things work and share his knowledge.

Twelve-year-old Annabell loves the seaside but lives in Milton Keynes, miles from the coast. She would like her very own beach den where she can spend time with friends and relax.

Stan from Cumbria is a talented artist and a huge fan of comics. However, he has nowhere to draw and needs a den to work on his illustrations and display his art.

Twelve-year-old Amelia from Glasgow has family ties to Australia, the USA, China and Hong Kong, and she wants a den where she can celebrate her diverse international heritage.

Ollie wants a lucky cat-themed den where he can relax, hang out with his favourite feline Graham and work on his very own comic stories.

Lydia from County Durham is passionate about the ancient Egyptians and wants an appropriately themed den where she can learn more about this fascinating period from the past.

Joe and Meryl take a look back at some of the amazing dens from past series and catch up with some of our Dengineers to see how the dens have changed their lives.

Joe and Meryl take a look back at some of the amazing dens from past series and catch up with some of our Dengineers to see how the dens have changed their lives.

Joe and Meryl take a look back at some of the fun moments and amazing dens from the series.