Holland is protected from the sea by a long line of coastal dunes. Most of the land area behind the dunes consists of polder landscape lying well below sea level.
At present the lowest point in Holland is a polder near Rotterdam, which is about seven meters below sea level.
Continuous drainage is necessary to keep Holland from flooding. In earlier centuries windmills were used for this task. The landscape was (and in places still is) dotted with windmills, which have become a symbol of Holland.
Holland is 7,494 square kilometres (land and water included), making it roughly 13% of the area of the Netherlands.
Looking at land alone, it is 5,488 square kilometres in size. The combined population is 6.1 million.
The main cities in Holland are Amsterdam, Rotterdam and The Hague. Amsterdam is formally the capital of the Netherlands and its largest city.
The Port of Rotterdam is Europe\'s largest and most important harbour and port. The Hague is the seat of government of the Netherlands.
These cities, combined with Utrecht and other smaller municipalities, effectively form a single city—a conurbation called Randstad.
The Randstad area is one of the most densely populated regions of Europe, but still relatively free of urban sprawl. There are strict zoning laws.
Population pressures are enormous, property values are high, and new housing is constantly under development on the edges of the built-up areas. Surprisingly, much of the province still has a rural character.
The remaining agricultural land and natural areas are highly valued and protected. Most of the arable land is used for intensive agriculture, including horticulture and greenhouse agri-businesses.