Andernach Geyser

The Andernach Geyser, located on the Namedyer Werth — a Rhine peninsula near the town of Andernach — is the world's tallest cold-water geyser, shooting water 50 to 60 meters into the air. First drilled in 1903, it owes its explosive force not to volcanic heat but to the enormous pressure of dissolved carbon dioxide rising from the volcanic Eifel bedrock beneath the Rhine. The geyser erupts roughly every two hours and is only accessible by pre-booked boat tour (daily 09:00–17:00), which keeps the peninsula in a near-pristine natural state. The short Rhine crossing delivers open views of the Mittelrhein valley, and the eruption itself — though lasting just a few minutes — produces a column of water and mist tall enough to be visible from a considerable distance.