History puzzle solved

Today is a national holiday in Spain, so shops and banks are shut. It's also been overcast and dull, so little incentive to get out and go anywhere special. I took time to write my Sunday sermon in the morning, and after cooking lunch, I settled down to see if I could find out anything about the very large mysterious ruined building by the coast road outside Garrucha.

Eventually, I tracked down an old website, many Google search pages deep, recounting the history of an industrial railway line, built around 1890, running from lead mines 17km inland at the small town of Bédar, down to the shore at the southern end of Garrucha. The site has photos taken at the turn of this century of the ruins of what had been a lead smelting plant. Its product was loaded on to boats on the sea shore another hundred meters away. The mines closed in the 1920s and with them, the railway disappeared. 

The land above and beyond the smelting plant had other industrial buildings on it, now long gone. A large area of old industrial land has cleared, maybe with housing in mind in the long term. What remains of the old smelter has been been tidied up, and enhanced with gardens. But curiously, no easily available information publicises this aspect of the town's heritage, whose wealth creation, over a century ago, helped transform a small fishing town with a mineral shipping business into a stylish resort with reputable restaurants and small hotels.

I'm so pleased to have solved this little puzzle. My initial conjectures about a vaulted roof were far from the truth. The neatly laid stone blocks over the site behind the standing end walls were most likely to cover a mound of rubble from the demolished side walls of the building - perhaps cheaper than the cost of taking away the demolition rubble, but maybe also securing toxic waste contamination from furnaces originally housed there. Re-purposing land after industrial use is just as complex and potentially expensive a planning issue as any other form of waste processing with environmental impact.

When I went out at tea time to get some fresh air, I found there'd been light rain. Pavements were still drying, and the air smelled fragrant and fresh. I went down to the beach and walked around the periphery of the nature reserve, exploring paths through the bushes and tall grasses surrounding the lake above the sea shore where the Rio Aguas stops, and seeps water through the sand into the beach. I've come to the conclusion this uncommon environmental feature is not entirely natural. 

If it was there originally on its own, it's been enhanced by constructing two metre dykes along a kilometre of its length inland. On the beach itself the sand bar rises only half a metre from the water level. But this has been sufficient to foster vegetation growth in an extensive area of beach around, thanks to colonising plants. I noticed among the tallest grasses and canes growing shore side, lots of pebbles, washed up with sand at high tides in stormy weather, helping to re-enforce the enclosure of river water to create a lake.

On the north side, I found a path beneath the road bridge over the lack which led through the vegetation to the water's edge, under the bridge. A man was fishing there. There was no need to acknowledge each other as we both needed silence. Then a host of egrets returned to roost for the night, attaching themselves to waterside rushes where they could, hundreds of them. Hordes of swifts came, bats as well, to feed on myriad insects, while coots fought over space in the water below. I realised that in the evening and early morning, days earlier, I'd been mistaken about the waterside plants, viewed from a distance. They were not exuding any white cottony substance. All the white blobs on reeds which were in my field of view in low light were birds roosting, trying to be as inconspicuous as possible. Well, they fooled me.

While I was there, I heard several different bird calls I couldn't identify any more than I could see them. I got one new bird photo, however. I think, a reed warbler. If you know differently, tell me