Most decent sized Mexican towns have at least one mercado (market), where vendors come to sell foods and wares of a dizzying variety. Guanajuato is no exception. Mercado Hidalgo, which marks the unofficial eastern edge of the Centro, is a cavernous T-shaped building with an arched roof. Originally intended to be a train station (not hard to imagine from inside or out), the main entrance and clock face of Mercado Hidalgo were designed by Alexandre Gustave Eiffel (he has a slightly more famous piece in Paris bearing his name). After five years of construction, the Mercado was officially opened in 1910 by President Porfirio Diaz as part of Mexico’s centennial celebration. The interior is dim, but not dark, and crammed wall to wall with all kinds of stalls; fresh produce of all varieties, butchers, shoes, clothes, crafts, flowers, souvenirs, and even places serving hot food and cold drinks that are almost always packed with locals. It’s full of smells, both good and bad, and you have to choose your produce with care (the mangos are amazing right now, the pineapples not so much), but the prices are great, and if you want to understand Guanajuato you must stop here at least once.