Midsummer images from here.
Glad midsommar! (Happy Midsummer!).
"In modern Sweden, Midsummer's Eve and Midsummer's Day (Midsommarafton and Midsommardagen) [...] is arguably the most important holiday of the year, and one of the most uniquely Swedish in the way it is celebrated, even if it has been influenced by other countries long ago.
The main celebrations take place on the Friday, and the traditional events include raising and dancing around a huge maypole. One typical dance is the frog dance. Before the maypole is raised, greens and flowers are collected and used to cover the entire pole.
Raising and dancing around a maypole (majstång or midsommarstång) is an activity that attracts families and many others. People dancing around the pole listen to traditional music and many wear traditional folk costumes. The year's first potatoes, pickled herring, sour cream, and possibly the first strawberries of the season are on the menu. Drinking songs are also important at this feast, and many drink heavily.
Because Midsummer was thought to be one of the times of the year when magic was strongest, it was considered a good night to perform rituals to look into the future. Traditionally, young people pick bouquets of seven or nine different flowers and put them under their pillow in the hope of dreaming about their future spouse. In the past it was believed that herbs picked at Midsummer were highly potent, and water from springs could bring good health. Greenery placed over houses and barns were supposed to bring good fortune and health to people and livestock; this old tradition of decorating with greens continues, even though most don't take it seriously."
To learn more about the Swedish Midsummer traditions continue reading here or here for example.