Rijnwoude was a municipality in the western Netherlands, in the province of South Holland. The municipality covered an area of 57.89 km2 (22.35 sq mi) of which 1.20 km2 (0.46 sq mi) was water.

Koudekerk aan den Rijn is a village located in the municipality of Alphen aan den Rijn, Netherlands. It is located about 4 km west of the urban centre, in the province of South Holland.