It does perhaps not look like much in the photo above, but it is the most powerful cold-water geyser in the world. The problem is that the Photo Of The Day needs to be in landscape format and, obviously, a proper geyser at full tilt is much taller than it is wide. The shot was taken just before the eruption finished.
The next photo gives a better impression of its size – when it is close to the top of the cycle.
The jet erupts around every 2 hours and rises up to a height of some 60m, which is a world-record for a cold-water geyser. (However, it stays that high only for a fairly short time.)
The geyser is located on a narrow peninsula jutting out into the Rhine, just north of the little town of Andernach – which in turn lies around 20km northwest of Koblenz. There is a visitor centre in the town, providing some interesting exhibits and background information about the geyser. It is also where you get your ticket (and some refreshments, if you wish). The ticket price includes the brief ferry ride to the site of the geyser itself.
When you get there, all you see is a pile of stones. Then the first signs of something happening emerge …
… and very quickly the column of water rises …
… before subsiding again after a few minutes.
Note the strangle bubbles in this last (and the very first) photo – it looks as if somebody has added a bit of foam bath liquid to the water, but the effect is due largely to the carbon dioxide dissolved in it. During the first half of the 20th century various owners/licensees actually extracted carbon dioxide and mineral water from the site.
The geyser is quite a popular attraction, especially at weekends, and it is advisable to book ahead. The link below provides more information:
https://www.geysir-andernach.de/?L=1
The town of Andernach is a pleasant little place offering enough to keep you occupied for an hour or two, either before or after a visit to the geyser. Pictured below is its cathedral (Mariendom).