Korsør Fæstning is a historic fortress located in Korsør, Denmark, now integrated into the city and transportation museum that documents the local area's maritime and urban heritage. The fortress served strategic defensive purposes historically, commanding important coastal positions. Today, the site operates as a museum venue, offering visitors insights into Korsør's role in Danish history and its significance as an over-fartssted (passage point). The museum provides exhibitions and interpretive experiences related to the fortress's military importance and the city's development, making it an educational destination for those interested in Danish military history and local cultural heritage.