What's the English for tężnia?

This (below), dear readers, is a tężnia (pron. 'TENZH-nyuh'. Something that's well known to Poles, entirely unknown to Brits. This one is in Konstancin, a posh(-ish) exurb of Warsaw, which were it situated in England would be known as a spa*. The town of Konstancin was set up in 1897; before WWII, there was a sanatorium here as well as many villas belonging to the well-off.


Central to Konstancin is the spa park; central to the spa park is the tężnia, and central to the tężnia is a device (in Polish grzybek - lit. 'little mushroom'), left, that vaporises mineral water coming up under pressure from deep underground, creating a salty mist. The tężnia itself is a wooden construction that reminds me of Shakespeare's Globe Theatre stuffed with twigs. Mineral water, rich in bromide and iodine, trickles down the twigs and evaporates in the sun, leaving salt deposits on the twigs. Now, abiding in this environment is supposed to be healthy.

The interesting thing is that Polish doctors actually prescribe fortnightly stays at sanatoria such as Konstancin - paid for by the national health fund.

The park and the tężnia is open to one and all, and people of all ages come to enjoy the tężnia. You are only supposed to be in the vicinity of the grzybek for 15 minutes at a time, and within the tężnia itself for an hour. Entry is 9 zlotys (two quid), concessions for the young, old and infirm, open from April to October.

View from the outside of the tężnia, looking in. Note the lightning conductor running along the top. If you think this tężnia looks cool, you should visit Ciechocinek, 20km south south-east of Toruń; the sanatorium there has three tężnie (plural), in total 1.7km long and 16m high - these are the world's largest.

OK, so what is tężnia in English? Well, in German, it's gradierwerke (the Germans invented them in the 17th C.). There are several in Germany. In English, then? According to Wikipedia, it's graduation tower. But I don't think that makes any of my UK, US, Canadian or Australian readers any the wiser!

*Think of Royal Bath Spa or Harrogate Spa transplanted to Croydon to get an idea of Konstancin's place in Warsaw's consciousness. And to my Polish readers: the word 'spa' should not be capitalised (SPA) - the letters are not initials!

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