Netherlands is a constituent country of the Kingdom of the Netherlands, consisting of twelve provinces in western Europe and three islands in the Caribbean. The European part of the Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east; and shares maritime borders with Belgium, Germany and the United Kingdom. The country is a parliamentary democracy organised as a unitary state. The capital city of the Netherlands, mandated by the constitution, is Amsterdam, however, the seat of government is located in The Hague. The Netherlands in its entirety is often referred to as Holland, which in strict usage, refers only to North and South Holland, two of its provinces; however the former usage is generally accepted. The Netherlands is a geographically low-lying country, with about 20% of its area and 21% of its population located below sea level, and 50% of its land lying less than one metre above sea level.