Each year, around the winter solstice, the Cathedral of Mallorca offers us the spectacle of a giant kaleidoscope of color. Light rays enter in a perfect way through the major rosette, the one of the altar, and out of the main door rosette, the western one, so that a colored cylinder is created.
The Es Baluard Museum and the Balearic Mathematical Society (SBM-XEIX) organize the observation of the lighting effect from the museum's terraces, located in the bastion of Sant Pere, one of the places where the phenomenon is best enjoyed.
After the observation, is held at the Es Baluard Aljub the conference La orientación de las iglesias mallorquinas y los consecuentes efectos lumínicos (The orientation of the Majorcan churches and the consequent lighting effects) by Joan Serra Busquets.