Mexico's Yagul caves and Silver Route now World Heritage sites

When I first started traveling in Mexico, I got excited every time I learned I was near a UNESCO World Heritage Site. I would find my way there no matter how many dusty, rocky goat trails I was required to travel. It soon seemed that that no matter where I went, a World Heritage site was waiting nearby (many of them, thankfully, along perfectly decent roads).

There's a good reason for that. Mexico has more World Heritage Sites than anywhere else in the Americas, and is sixth among the 151 countries worldwide that have recognized sites. With the listing of two new locations this month, one along Mexico's famous silver route and another in central Oaxaca state, Mexico now claims 31 of all the world's 911 World Heritage sites.

UNESCO began in 1972 to identify sites around the world that constitute an irreplaceable trove of humanity's cultural and natural heritage. By naming such places to the World Heritage list, the agency aims to protect and maintain these properties that "belong to all the peoples of the world, irrespective of the territory on which they are located." Selected sites must be of "outstanding universal value" and represent human creative genius, exceptional cultural development or record of natural history. UNESCO provides planning, management, educational and technical assistance and training, and sometimes funding, to conserve these places.

Among Mexico's World Heritage Sites are well-visited locations such as the hauntingly beautiful ruins at Palenque, the agave fields of Tequila, the Sian Ka'an Biosphere Reserve, the ruins of Chichen Itza and Calakmul and historic centers of Mexico City and some of the country's most beautiful colonial cities, including Campeche, Morelia and Puebla. Others are of more interest to historians and archaeologists. The Campus of the Universidad Nacional Autonoma de Mexico, the early 16th century monasteries on the slopes of Popocatepetl or the Rock Paintings of the Sierra de San Francisco, for example, have many fans within a narrower spectrum but don't make it onto the usual "must-see" list.

Mexico's newest listings have a bit of both.

El Camino Real de Tierra Adentro

The "Royal Inland Road" is an 869-mile section of the famous Silver Route, which stretches 1,615 miles from Mexico City to New Mexico in the United States. It is unusual among World Heritage sites for encompassing so much of the country, rather than a single site, and for containing five cities (San Miguel, Guanajuato, Mexico City, Zacatecas and Querétaro) that have already been named to the list individually. The route was used from the mid-16th to the 19th century to transport silver mined from the hills around Zacatecas, Guanajuato and San Luis Potosi, as well as mercury imported from Europe. Though its primary activity was commercial, the route also created social, cultural and religious connections between Spanish and Amerindian cultures.

Traveling through nine states and the Federal District, the listing adds another 55 sites to the five existing World Heritage sites. These include the cities of Durango, Aguascalientes and San Luis Potosi, as well as numerous bridges, haciendas, chapels, temples and even a hospital. El Camino Real de Tierra Adentro follows a path quite similar to one of the government's new Tourist Routes, A Colonial Experience. The World Heritage designation, however, has been in the works over the past 10 years.

Prehistoric Caves of Yagul and Mitla in the Central Valley of Oaxaca