Boskoop is a town in the province of South Holland. It was a separate municipality until it merged into Alphen aan den Rijn in 2014. The town had a population of 15,050 in 2012 and covers an area of 7.29 km2 (2.81 sq mi) of which 1.39 km2 (0.54 sq mi) is water. It's the world's biggest joined floriculture area.

Alphen aan den Rijn is a city and municipality in the western Netherlands, in the province of South Holland. The city is situated on the banks of the river Oude Rijn, where the river Gouwe branches off. The municipality had a population of 112,587 in 2021, and covers an area of 132.50 km2 (51.16 sq mi) of which 6.27 km2 (2.42 sq mi) is water.