San Luis Potosí on the Mercury and Silver Route of the Intercontinental Camino Real


San Luis Potosí on the Mercury and Silver Route of the Intercontinental Camino Real has been part of the Tentative list of Mexico.

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UK - 28-May-09 -

San Luis Potosí on the Mercury and Silver Route of the Intercontinental Camino Real (T) by Solivagant

It seems likely that the “Mercury + Silver Binomial etc…” nomination will get inscribed at the Seville WHC. If so, it will be the most geographically spread of any WHS and will extend across Slovenia, Spain and Mexico. The general “story” is that mercury mined from Idrija in Slovenia and Almadén in Spain was taken to San Luis Potosi in Mexico to assist the process of extracting silver from the ore mined there and the silver was then returned to Europe using the “International Camino Real” in each direction.

We haven’t yet heard that ICOMOS has de/referred it and it does seem to press all the right buttons UNESCO policy-wise with its trans-national nature. A potential problem might be whether it has proven possible to get the 3 states involved to produce a fully compliant set of dossiers and management regimes! To help this in Dec 2007 they even signed a separate Tripartite Agreement.. (Nb. Peru had also been asked to join with Huancavelica which was/is not yet on its T List but declined). As an aside - I find the title of the site (“Mercury and Silver Binomial”) somewhat perplexing. I guess “binomial” (= “2 terms”) refers to the 2 metals but why adopt this term which would normally only be used in a mathematical or biological sense in English? What does it add?

Adjidra and Almadén consist mainly of sites of industrial archaeology related to mining plus each of the town centers. That of San Luis Potosi (SLP) however consists solely of the colonial town centre with no mines - an interesting gap which perhaps needs some explaining (see later)! An extra complexity is that the SLP and Almadén inscriptions include “identifiable mercury and silver royal road from the Real Caja in San Luis Potosí City to Mexico City into the proposed core zone” and “Identifiable stretches of the road to Seville, city from which the mined mineral was shipped to America”. These could extend the inscribed areas significantly further!

Reviews will be needed from each country to get a clearer picture of what the full site involves as we personally can only supply one for SLP which we visited in Mar 2008 between a series of other WH-inscribed colonial cities from Central Mexico i.e. Morelia, Zacatecas, Guanajuato and Queretaro. These are all within a day’s drive or less of SLP. And therein lies the problem regarding SLP’s merits – how to differentiate it from all these others? That said, its centre is remarkably pleasant and even peaceful for an industrial city whose “greater area” has around 1 million inhabitants. Certainly, take it in if you are passing by - but a Guanajuato or even a Zacatecas it is not. The largely pedestrianised centre has around a dozen mainly 17th and 18th century churches, some imposing public buildings from those eras or later and numerous plazas (photo) – it certainly reflects its history as a centre of wealth.

But a WHS? Well the Mexican government must have faced a bit of a problem there, having already inscribed so many other colonial cities in the area. What “edge” could be found for SLP? Even its “silver” heritage per se doesn’t stand out in competition with Guanajuato and Zacatecas! Yet the state of SLP has no WHS and it does seem to be Mexico’s policy to try to get a site in every state – and, preferably, including each state capital. So, what about its “silver credentials”? The T List description twice uses the phrase “the historical urban-mining set of SLP” - but in fact no mining ever took place there. The State of SLP has many mining towns (Real de Catorce around 200kms away is considered the “best” – though we didn’t visit it) but the nearest mine to the capital was/is at Cerro San Pedro 12kms away (discovered 1592 – the mines at Zacatecas had been discovered as early as 1546). SLP itself was set up later because of the lack of water at San Pedro. I now understand it to be a place worth visiting but our guide books didn’t really mention it and neither did the SLP tourist office so I am afraid we didn’t. But you might have thought that the SLP inscription would have included it – just as the mines in Adjidra and Almadén are included? Well not really! It turns out that the locals have been fighting a long battle with the Canadian company operating the mine, over its environmental practices which include leaching by cyanide with potential risk to the water supplies of nearby SLP. No wonder ICOMOS was kept well away from all this!

It is perhaps interesting to note that the 3 sites in this nomination were only put on the T List of their respective countries in mid 2007 – that, compared with the normal pace of such matters, is a real “fast track” through to a nomination for 2009 which required documents to be submitted in 2008! Mexico must have been quite pleased to have been asked by Spain in 2006 to think of joining in with a serial property related to silver and mercury along the Camino Real. So why waste such a good idea by using the already inscribed silver centres of Zacatecas or Guanajuato as part of the serial transborder site when it could provide some great “cover” for the much weaker SLP! Certainly SLP was to a large extent originally founded on the wealth of nearby silver mines the but to call its centre a “historical-urban mining set” is to obfuscate – what on earth does it mean when no mining took place there!

In fact an early version of a Draft Nomination file for the Silver and Mercury Binomial is available on the Web. It is not precisely dated but, from various clues, must have been put together in the second half of 2007 – i.e. before the tripartite agreement was signed. As such it includes a significant amount on the Peruvian town of Huancavelica which was ultimately excluded and will have needed significant changes (it could be worth downloading this version to compare with any final version!). In it, the inclusion of SLP is justified as

“San Luis Potosí is a significant exponent of a mining town exemplifying the process of silver amalgamation using mercury and its corresponding organization with respect to the production, transportation and distribution of both products and the sharing of their profits. It is an exceptional case of a territorial system created through the foundation of a city designed to respond to a whole set of mines working the silver obtained through amalgamation with mercury.”

I don’t find this statement convincing and feel that, if SLP does get inscribed, it will be more because of Mexico’s WHS policies than because of its OUV let alone its pre-eminent status within the Silver and Mercury Route.

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San Luis Potosí on the Mercury and Silver Route of the Intercontinental Camino Real
2013 Removed from Tentative List

2010 Deferred

2009 Referred

2007 Revision

Includes former TWHS Ciudad Hist

2007 Added to Tentative List

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