Kiesgrubensee Gremberghoven, Nature reserve in Cologne, Germany.

Kiesgrubensee Gremberghoven is a protected area in Cologne created from a former gravel pit that now spans several dozen hectares. The site features lakes, wooded sections, and open meadow areas that together form a functioning ecosystem.

Gravel and sand were extracted here by the Cologne dredging firm Dr. Matthias Alberty, which gave the lake its local name Alberty. The pit was closed in the 1980s and designated a nature reserve in 1989. The site was then left to natural succession, with fences and restrictions on fishing and leisure use.

The name points to the gravel pit from which this lake was created, showing how nature reclaims spaces once used for work. Walking around today, you see water surrounded by woods and meadows that shelter birds and insects.

The site is easily reached by public transport from central Cologne and features marked trails for walking through the area. The paths lead through different sections and are easy to navigate.

The area shows clearly how industry and nature can coexist when people intentionally make room for it. Today, rare bird species nest here that are hard to find elsewhere in the region.