South Holland (Dutch: Zuid-Holland [ˌzœyt ˈɦɔlɑnt] (listen)) is a province of the Netherlands with a population of just over 3.7 million as of November 2019[6] and a population density of about 1,373/km2 (3,560/sq mi), making it the country’s most populous province and one of the world’s most densely populated areas. Situated on the North Sea in the west of the Netherlands, South Holland covers an area of 3,419 km2 (1,320 sq mi), of which 605 km2 (234 sq mi) is water. It borders North Holland to the north, Utrecht and Gelderland to the east, and North Brabant and Zeeland to the south. The provincial capital is the Dutch seat of government The Hague, while its largest city is Rotterdam. The Rhine-Meuse-Scheldt delta drains through South Holland into the North Sea. Europe’s busiest seaport, the Port of Rotterdam, is located in South Holland.

Archaeological discoveries in Hardinxveld-Giessendam indicate that the area of South Holland has been inhabited since at least ca. 7,500 years before present, probably by nomadic hunter-gatherers. Agriculture and permanent settlements probably originated around 2,000 years later, based on excavations near Vlaardingen. In the classical antiquity, South Holland was part of the Roman Province of Germania Inferior, and the border of the Roman Empire ran along the Old Rhine and reached the North Sea near Katwijk. The Romans built fortresses along the border, such as Praetorium Agrippinae near modern-day Valkenburg, Matilo near modern-day Leiden, and Albaniana near modern-day Alphen aan den Rijn. A city was founded near modern-day Voorburg, Forum Hadriani. It was built according to the grid plan, and facilitated a square, a court, a bathhouse and several temples.