HELIX AND DOUBLE HELIX IN THE METAEDER
THE DOUBLE HELIX AS A STAIRCASE
CHAMBORD CASTLE: DOUBLE-DOUBLE HELIX STAIRCASE (two superimposed helices which do not meet each other)
DOUBLE HELIX STAIRCASE
THE DOUBLE HELIX AS A WIND ROTOR
FOUNTAIN OF ORVIETO AS A DOUBLE HELIX
Helix and double helix are chiral, i.e. dextrorotatory or laevorotatory. The double helix is the geometrical figure of DNA.