Kolksluis, Lock bridge in Amsterdam, Netherlands

Kolksluis is a small lock and bridge on Zeedijk street in the center of Amsterdam, Netherlands. It crosses the Oudezijds Kolk, a narrow canal with old buildings and the back wall of the Basilica of Saint Nicholas rising on one side.

A crossing and water gate have stood at this spot since the 1600s, when covered bridges and lock gates were drawn by local artists. The current concrete bridge dates from the late 1960s and reused parts of the older structure, while the lock continues to help manage water levels.

The name comes from the Dutch word kolk, which describes the whirl of water when a sluice opens. Standing on the bridge, you can hear the rush of water and watch small boats and barges move through, while neighbors pause on the quay to look on.

You can walk onto the bridge from Zeedijk or stand on the sidewalk near Prins Hendrikkade for a clear view along the water. The crossing is open to pedestrians and bicycles, but the paving is narrow in places, so step carefully when boats pass below.

When the lock opens, the water can be heard rushing through the narrow channel below the bridge, a sound that hints at the old system once used to flush the canals toward the sea. Photographers sometimes line up the sluice and the Old Church southward across the water for a view that has appeared in images for over a century.