On the equinox the sun is positioned directly over the equator. The word “equinox” means “equal night” because on the equinox the night is equal in length to the day. There are two equinoxes during the year, the spring equinox, sometimes called “vernal equinox,” which falls around March 20th and the autumn equinox which falls around September 23rd. The day of the spring equinox marks the end of winter and beginning of spring. The spring equinox is celebrated in many traditions as a time of fertility, regeneration and rebirth. Easter is calculated according to the date of the Spring Equinox – in the Western Church Easter falls on the first Sunday following the first full moon after the Spring equinox (the Eastern Orthodox Church celebrates Easter on a different date). Chichén Itzá is amongst the greatest surviving monuments of the Mayan civilisation. During the spring equinox, thousands gather to witness a phenomenon of light and shadow: the ‘plumed serpent’ of light descending the steps of El Castillo pyramid. The snake-like light phenomenon is created by an undulating pattern of sunlight on the edge of the pyramid’s steps. According to Mayan legend, the 34m-long ancient ‘serpent’, Kukulkan, is making his way to the well of sacrifice nearby… For many, watching the Spring Equinox is a spiritual experience – and here in Chichén Itzá, among locals, happy-snappy tourists and media, you can’t fail to notice the white-clothed religious groups who pray and sing to their gods, believing in the holistic healing and energising effect of the Equinox. As the sun breaks through the clouds to reveal the eagerly awaited ‘serpent’, most of the crowd fervently clap and cheer, but others stand in awed silence. The idea that a civilisation which evolved as early as 1500BC managed to concentrate its energies in building a monument of incomprehensible scale to highlight the time of year when the hours of daylight and darkness are equal is extraordinary. Get there early to avoid the midday heat and ensuing crowds.