This year marks the 15th summer since the Serpentine Gallery in London's Kensington Gardens started commissioning artists, designers and architects to create one-off, pop-up structures in its back yard. Up for just a few short months, the Serpentine Pavilion always draws a crowd and has a reputation for producing some of the most avant-garde, innovative, and weird and wonderful structures in the world – just for the fun of it. Well, why not?

Out & About: Serpentine Pavilion

Free to visit, this year's pavilion is the brain-child of Spanish architecture duo SelgasCano. Formed of a series of tunnels made from layers of opaque and transparent material stretched over a metal frame, visitors can enter and exit the structure from several points. Like a cross between a sci-fi fantasy and a child's den, a kaleidoscopic journey of light and colour awaits each pavilion-goer – at the heart of the structure is an open space for gathering as well as a café. Get ready for lift-off.

If this catches the imagination of budding young architects, check out the Build Your Own Pavilion Young Architect Challenge, a competition for 8-14 year-olds, which runs from 22nd June until 8th October. There's also more for grown-ups too - hear the architects behind the design in conversation with the Serpentine Gallery directors in the space itself on the 23rd June.

See what else is going on and take a look at our other Out & About articles about Grayson Perry's House for Essex and the Design Museum's Designs of the Year 2015.