Arriving 375 years ago on the Kalmar Nyckel, the first Europeans settled the Delaware Valley. To celebrate the occasion, the public is invited to Colonists' Day on April 13. At 11 a.m., a commemorative ceremony will be held at "The Rocks,� Fort Christina Park, where the Swedes and Finns landed. Musical entertainment, historical exhibits, reenactments, colonial craft demonstrations, hands-on activities, Swedish meatballs and baked goods will be available. Admission is free, although donations are welcome.