Hellevoetsluis (pronunciation (help·info)) (population: 40,164 in 2004) is a town an municipality on Voorne-Putten Island in the western Netherlands, in the province of South Holland. The municipality covers an area of 46.14 km² (17.81 mile²) of which 14.57 km² (5.63 mile²) is water. The name translates as "lock at the foot of the Helle". The Helle was a small local river which disappeared over time.