Fort Buitensluis, and hewt Hollands Diep near Numansdorp, aerial view of a fort of the Stelling van het Hollandsch Diep and the Volkerak

Fort Buitensluis, Numansdorp, is a fort of the Stelling van het Hollandsch Diep and Volkerak. The earthwork was constructed in the late 18th century, in the mid-19th century the bombproof rooms and the guardhouse were built (c) June 15, 2022 Aerophoto-Schiphol | aerial view 308574