Bergse Achterplas is one of two peat lakes that together form the Bergsche Plassen, tucked between the northern Rotterdam districts of Schiebroek and Hillegersberg.

Covering roughly 46 hectares, it is reachable by boat via a tunnel beneath the Straatweg, an extension of the Prins Bernardkade.

The lake is dotted with numerous small islands, many of which host compact recreational cottages managed through Watersportvereniging Ons Buiten, which leases the islands from the municipality of Rotterdam.

In summer, small boats weave constantly between the islands as residents and visitors travel to and from their cottages.

Navigators are advised to reduce speed and proceed carefully, as the waterways among the islands feature many blind bends and intersections.

Often described as one of Rotterdam's best-kept secrets, Bergse Achterplas offers a quiet, distinctly rural atmosphere surprisingly close to the city center.