Dörentrup is a municipality in the Lippe district of North Rhine-Westphalia, Germany.

The name is derived from the Low German word for hill passes, Dören.

Inhabitants can then request that lights be turned back on as needed by sending a code to a special phone number called Dial4light.

Each street has its own code that can be found either online on a specific website or on each light post.

This is intended to reduce energy use, save money, respect the nocturnal fauna and avoid light pollution.