Under the motto "Water and Sustainable Development" Bulgaria marks the World Water Day on March 22. The idea to celebrate the day emerged at the United Nations Conference on Environment and Development (UNCED) in 1992 in Rio de Janeiro, Brazil. One of the main objectives of the World Water Day is to focus efforts on preserving water resources. World Water Day is celebrated in a number of cities with exhibitions, competitions and mass events related to the topic. An exhibition entitled "Water Fountains of Bulgaria," organized in Sofia, has raised considerable interest. Many of the photos on display are related to historical events and various legends.