The Kylver Stone Letter is an ancient runic inscription found on a Swedish island in the Baltic Sea. It is believed to be one of the oldest known runic inscriptions, dating back to the 5th century AD. The term 'RUNE' is used to describe the characters of the ancient Germanic alphabet, which were used for writing and communication in Northern Europe before the Latin alphabet was adopted. The Kylver Stone Letter is an important archaeological artifact, as it provides insight into the language and culture of the people who lived in the area during that time period.