The Dengineers

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.

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 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.

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.

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.

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.

Ballroom dancer Harry from Dudley is a huge fan of Strictly and wants a den full of glitz and glamour to help him practise his dancing and store his trophies.

Bea from Hull and her best friend Stanley the sausage dog are seriously short of space. They need a den where they can learn new tricks and hang out together.

Siblings Nethuni and Abheetha are obsessed with optical illusions and want a den where they can work together to create new tricks to dazzle their friends.