The Hollandia is a historic drainage mill located on Loodijk in the town of Ankeveen. The mill was built in 1640, and was used to drain water from the land to form polders – areas of land reclaimed from the water, and protected by dikes. The mill was restored in 1766, and is no longer in active use. There are currently around 1000 historic mills remaining in the Netherlands, and the Dutch Windmill Society aims to preserve the mills that are still standing.