Much of the Netherlands lies below sea level, and waterlogged fields have always been a problem. The country was once dotted with windmills that powered pumps used to drain water from marshy land so it could be farmed (a job done with modern machinery today). Most of the old windmills are gone, but outside the village of Kinderdijk near Rotterdam, 19 windmills built in 1738 still stand. Carefully restored and staffed by volunteers, they take turns running, a few every day, for the sake of visitors. Two of them are also open to the public to see inside. It's one of the best places in the Netherlands to see a group of traditional windmills still operating in a rural setting.