The document provides information about the Netherlands. It notes that the Netherlands and Holland are not synonymous, with Holland referring to the western coastal region. It was the first country to legalize same-sex marriage in 2001. The Dutch are the tallest people on average in the world. The Netherlands has over 4,000 km of navigable waterways. Its highest point is only 323 meters above sea level. Rotterdam is the second largest port in the world. The Netherlands has been a constitutional monarchy since 1815 and a parliamentary democracy since 1848. Over 30% of the country lies below sea level, so it has extensive waterworks to prevent flooding from the sea and rivers.