Illumination of more than 18,000 architectural monuments will be turned off on the planet as part of the most massive environmental campaign “Earth Hour”. More than 2 billion people from 188 countries of the world take part in it. In 2019, the International Earth Hour will be held for the 13th time - the campaign will be held on Saturday, March 30. Everyone can take part in it, it is only necessary to turn off the lights and household electrical appliances from 8:30 pm to 9:30 pm.