Alblasserdam is a town and municipality in the western Netherlands, in the province of South Holland. It covers an area of 10.06 km², of which 1.28 km² is water, and has a population of 20,069 as of 2019. Alblasserdam is officially a part of the Drechtsteden region. A portion of the small village of Kinderdijk, which boasts the largest and most famous concentration of windmills in the Netherlands, is part of Alblasserdam.