The Cave

Discover the secrets of light in the Cave!

Play around with the light, experiment with different colour combinations and learn about optical illusions.

Concepts covered

  • Colours
  • Optics
  • Exploration
  • Light
  • Imagination

A fully immersive experience bursting with magic, poetry and colour!

Colours that change, colours that don't exist, colours that appear, colours that disappear. Delve deep into an intriguing and mysterious place and watch spectacular colour phenomena unfold as you try your hand at thrilling experiments! “Around the fire”, discover the surprises that the team of science communicators have in store for you. Listen carefully to the Shaman, the colourful character who lives in the Cave, and she will tell you her story. Get ready for a sensational sensory experience like no other, as the illusion of colours holds you well and truly spellbound!

Did you know?

A digital image is made up of millions of coloured dots: called pixels. Each one comprises 3 red, green and blue subpixels which, between them, can produce all the other colours.

Some experiments

Mix & match

Can you recreate an exact colour? Using the measuring buttons, mix the primary colours red, green and blue or cyan, magenta and yellow to try and work out which mixture recreates the colour shown. Well done, now you know what the trichromatic theory of colour vision is! In pairs, will you be able to “mix & match” the colours faster than your opponent? Compare your results and gain awareness of the differences in our individual perceptions: for we do not all see colours in the same way.

Coloured shadows

Enter the Cave and immerse yourself in the circle of white light. Inside the circle, and depending on your position, your shadows will multiply and appear in different colours: red, green, blue, cyan, magenta, yellow and black. This is the principle of additive colour mixing, used by television screens and computer projectors and monitors, demonstrated to entrancing effect!


Give free rein to your imagination as you create dot-to-dot light drawings using small colour cylinders. Signs, images or more abstract forms will appear, disappear, merge or adjoin as you go, creating a collective and ever-changing cave fresco. A fun and visually appealing experiment for all ages!

Explore our exhibitions

  • Technology

    The Factory

    Discover the mechanisms of artificial intelligence, interact with machines and develop algorithms!

  • Water

    The Oasis

    Experiment with the wide-ranging possibilities offered up by water, in a simple and fun way.

  • Nature

    The Garden

    Set off in discovery of the fauna and flora at the Vaisseau!

  • Collaboration

    The Building Site

    Stack, balance, transport and use your imagination to build extraordinary houses.

  • Discover all our exhibitions