The Dengineers build 11-year-old Ben a camouflaged adventure bunker.

Sibling rockers Sami, 9, and Nadia, 12, need their own soundproofed rehearsal room.

A massive Manchester United fan, 10-year-old Billy is in need of a football den.

Ella wants a den to escape the 35 bikes that are kept in every room of the house.

Jazz and Katelyn love dancing and want to put a dance studio in Jazz's mum's cellar.

Eleven-year-old Nathan wants a kitchen hangout, where he can practise being a chef.

Nyobi needs room, a desk space and art materials, for her design projects.

Ten-year-old Ben wants a den with enough room for his beloved train set.

Sienna really needs a new bedroom which can double up as a spy den, with lots of gadgets.

The pupils of the Lancasterian School want an exciting space that everyone can hang out in.

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

The Dengineers transform a youth centre's outside space.

The Dengineers build 10-year-old Aron his very own Bollywood den.

The Dengineers come to the aid of Carrie, a 10-year-old from Leeds who plans to celebrate her red hair with a gingerbread house den.

The Dengineers build 11-year-old Lola an old-fashioned cinema den.

Needing to go to hospital means Rufus often misses out on the play adventures he loves.

The team build 11-year-old Joshua his very own DJ den and take a visit of the BBC Radio 1 studios.

The team build 11-year-old Whitney her very own den to answer all her eco needs.

The team build 11-year-old Phillip his own den where he can build model planes.

Eleanor, 10, loves books, so the team bring the library to her - a magical library!

The team create a fantastic journalism den where Soibi can write news reports.

The team look back at all the amazing dens built throughout the series.

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.