Infiesto

Interior view of the municipal public laundry in Infiesto, Piloña. There´s a view of the water taps, looking towards the town, in extra.
The municipal washroom and water source was built by Infiesto in 1807, and was restored to its present state by the concejo, Piloña, in 2006. There´s a review of the structure here:s https://g.co/kgs/4tWvCkt
Infiesto has a river - the Piloña - running through it, and there are plenty of photographs (google for example those of Modest Montoto) showing people washing their dirty laundry in rivers from as late the 1930s, and doubtless it carried on beyond. Infiesto´s splendid laundry - by far the best I´ve seen -will have taken over from the river, which is perhaps 100 metres downhill, and will have been important till houses got their own water supplies. In the more rural areas that will mostly have been sometime around the 1950s but in Infiesto, the capital of the concejo, probably significantly earlier. 
I´ve found a few entries in Google that describe the structure, and none of them gives much authoritative detail - the one I´ve linked above is the best I´ve found. What I will say is that I´m sure the reconstruction is a better structure and more modern, than the original was; and that in the various times I´ve been up there I´ve never seen it in use or showing signs of having been used. The only exception is this time, when I found a sleeping bag and luggage tucked away in a corner, possibly but probably not in the expectation that they were going to be washed later.