St John's Day is the feast day of Saint John the Baptist observed by the Catholics and some Protestants in many countries on June 24.
This religious holiday is strongly connected with the pre-Christian Midsummer celebrations.
In ancient times, Midsummer was a festival of summer solstice, the longest day of the year.
Summer solstice was a special moment of the annual cycle.
People believed that on this day evil spirits roamed the Earth freely so they lit huge bonfires to protect themselves from evil.
When Christianity began to spread, many pagan celebrations merged with new Christian holidays.
Midsummer transformed into the nativity of John the Baptist, but many pagan traditions were preserved.
For example, bonfires are still lit in many countries.
St John's Day is particularly popular in Northern Europe, but it is also very strongly observed in some other parts of Europe as well as in the United States, Canada and some parts of South America.
Each country has its own Midsummer traditions.