Geysir Andernach

The Geysir Andernach, located on the Namedyer Werth peninsula in the Rhine near Andernach, is the world's tallest cold-water geyser, shooting plumes up to 60 metres into the air every 90 minutes or so. It was first drilled in 1903 when workers prospecting for mineral water accidentally tapped a CO₂-rich aquifer — natural gas pressure, not geothermal heat, drives the eruption, making its mechanism fundamentally different from classic volcanic geysers. The peninsula is only reachable by ferry from Andernach's old town, giving the excursion a distinctly off-the-beaten-path feel. A visitor centre explains the underlying geology, and the elevated viewpoint offers clear sightlines across the Rhine towards the medieval skyline of Andernach.