St. John's Day, also known as 'Joninės' or 'Rasos', is one of the most important and widely celebrated holidays in Lithuania. Observed on the 24th of June annually, St. John's Day marks the midsummer solstice and is closely linked to old pagan customs and rituals. This holiday, which is a public holiday in Lithuania, connects with old traditions of nature and folk culture. It is the celebration that brings people closer to nature and ancient customs.

The traditions of St. John's Day are rooted in rites and customs designed to ward off evil spirits, ensure fertility, and cleanse the soul. During this day, Lithuanians gather around bonfires, wear crowns made of flowers and oak leaves, and sing traditional songs. These songs often deal with astrological myths, historic events, and most often – romantic themes. A popular belief is that the dew on St. John's Day morning has healing powers, which is why many people wake up early to wash their faces in it.

One of the most interesting traditions is attempting to find the mythical 'fern flower' at midnight, a task considered impossible but signifies luck and prosperity. Other customs include jumping over bonfires, a symbol that purifies and rids of evil spirits, and floating wreaths in the water, a spectacle aimed to predict the future, especially regarding marriage and relationships. Despite the heavy influence of Christianity on Lithuanian customs, St. John's Day manages to retain the richness of its pagan roots giving it a unique traditional and cultural heritage value.