Bikevolution association, To Sustain the Nature in Bulgaria coalition and Bikearea association organised various events to mark and celebrate Earth Day on April 22, including a bicycle parade on Sofia’s streets. About 300 people attended the bike procession, which later merged into the march in Sofia’s centre, increasing the number of participants to more than 1000. Most of the environmentalists marching through the city streets were young students carrying a poster reading part of the Bulgarian constitution: 'Art.15. The Republic of Bulgaria ensures the preservation and the proliferation of the environment, the sustainability and variety of nature and the reasonable usage of natural treasures.' Participants later gathered for a concert in Borissovata Gradina to celebrate the event. For more information, please read the Sunday Blog on www.sofiaecho.com.