San Juan del Río is located about 40 kilometers east of Querétaro in the Mexican state of the same name and is about 150 kilometers from Mexico City. The industrial base of this city with approximately 150,000 residents has been growing rapidly, and its infrastructure is being modernized as well. Nevertheless, San Juan del Río has retained its rural character. San Juan del Río is located along the Camino Real de Tierra Adentro historical trade route and for this reason was designated a UNESCO World Heritage Site in 2010. The trade route linked Mexico City with silver mines in the north operated by Spanish colonial rulers. These mines stretched all the way to Santa Fe, which is now part of New Mexico in the US.