The Zwaanendael Museum was built in 1931 to commemorate the 300th anniversary of the state's first European settlement, Swanendael, established by the Dutch along Hoorn Kill (present-day Lewes-Rehoboth Canal) in 1631. Designed by E. William Martin (architect of Legislative Hall and the Hall of Records in Dover), the museum is modeled after the old stadthuis (City Hall) in Hoorn, the Netherlands, and features typical 17th century Dutch design elements including a stepped facade gable, terra-cotta (baked clay) roof tiles, carved stonework, and decorated shutters. The very top of the building's front features a sandstone statue of David Petersen DeVries, leader of the expedition that founded Swanendael. The face of the building is decorated with intricate sandstone carvings, including the coat of arms of the city of Hoorn.
The museum's exhibits and presentations illustrate the rich history of Sussex County by highlighting its maritime connections and by telling the stories of the people who lived and worked along Delaware's southeastern coast.