Netherlands means low-lying country; the name Holland was originally given to one of the medieval cores of what later became the modern state and is still used for 2 of its 12 western provinces. A democracy under a constitutional monarch, the kingdom includes its former colonies in Aruba, Bonaire, Curaçao, Saba, Sint Eustatius, and Sint Maarten. The capital is Amsterdam and the seat of government The Hague. The country is remarkably flat, with large expanses of lakes, rivers, and canals. Initially, man power and horsepower were used to drain the land, but they were later replaced by windmills, such as the mill network at Kinderdijk-Elshout, now a UNESCO World Heritage site.