Guanajuato (declared a “World Heritage Site” by UNESCO), is situated in the highlands of Mexico’s colonial heartland. With a population of 155,000, this beautiful city is a blend of both the old and the new worlds. The most important mining center in Mexico during the colonial period, Guanajuato still maintains its colonial charm with cobblestone streets and historic buildings that are relatively untouched by modern construction. Its intricate system of underground tunnels once helped divert the flooding of the Río Guanajuato. These tunnels now serve as the principal roadways within the city, creating a timeless appearance.