June 21 is World Hydrography Day. Annual celebration of this holiday emphasizes importance of hydrography particularly in protection of marine reserves and promotion of safe navigation in international waters and ports.
Fête de la Musique, or World Music Day, is one of the worldwide known music festivals, that is annually celebrated on June 21. The festival is organized in 110 countries around the world in more than 406 cities.
Go Skateboarding Day is an annual event, celebrated on June 21. This event is organized under initiative of the International Association of Skateboard Companies (IASC).
International Surfing Day is an unofficial observance, that celebrates the sports of surging, surfing lifestyle and sustainability of ocean resources. It's annually observed on summer solstice, that falls on June 21, and on June 20 on leap years.
World Humanist Day is annually observed on day of summer solstice, that usually falls on June 21. This holiday was created under initiative of the International Humanist and Ethical Union (IHEU).
The tradition of planting trees is very old in Cuba. The Cubans gathered to celebrate the first Arbor Day on October 4, 1904. However, during the next years the date was changed to its present-day June 21.
International Yoga Day is annually observed on June 21. This observance was established by the United Nations General Assembly on December 11, 2014.