Opperzau

Opperzau is a community of the German municipality Windeck, in the Rhein-Sieg district, in the south-eastern part of North Rhine-Westphalia.

In 1604, the settlement of Siegburg (Siegburger Vergleich) clarified the limit of the current federal states North Rhine-Westphalia and Rhineland-Palatinate which leads through the village and parted them into Opperzau (northern part) and Oppertsau (southern part).

The reason for this was a dispute of a territorial sovereignty that started in 1294, when the County of Sayn-Wittgenstein and other small counties claimed possession over parts of Berg and the Sieg districts.

Today, 200 meters of a road within the village mark the boundary between both federal counties, and have two different street names: Fürthener Straße for the Opperzau side and Siegstraße for the Oppertsau side.

Until 1993, Opperzau had a train stop, which is no longer used, due to a lack of passengers.