Bustling and broad, Tuxtla’s main plaza occupies two blocks flanked by an untidy array of concrete government and commercial structures. At its southern end, across Avenida Central, you’ll find nice hill views in front of the whitewashed modern Catedral de San Marcos . The cathedral’s clock tower tinkles out a tune on the hour to accompany a kitsch merry-go-round of apostles’ images, which emerges from its upper levels.