Built in 1626, it was and still is today a splendid building. The year 1626 - displayed both above the entrance door and on a plaque in the Stadhuiskade (Town Hall Quay) - verifies that this was an important building, erected at a time when the community was undergoing great economical growth. The coat of arms of both Delfland and the then District Water Board can also be seen above the entrance.

This interior is also nothing short of magnificent! The District Water Board's office boasts a beautiful old mantelpiece, carved beams and a spiral staircase. Today this building is principally used for representative purposes - even the chambers are sometimes used for carrying out wedding ceremonies.

The management of water has always played an important role in Maassluis. This applies not only to the streams but moreover to the inner-harbour, which has for centuries had to deal with the age-old problem of "silting-up". Many years ago it was possible to rinse out the inner-harbour during low tide. This was achieved by opening the bolts on the North and South "gussets" (the North gusset is still there but the South gusset has been filled in and is no longer in use). At the onset of low tide the bell at the back of the Public Land House (which is still there) was rung. This was to warn the ships that the "gussets" were to be opened, and hence the harbour "rinsed out".