Puebla’s impressive cathedral, which appears on Mexico’s M$500 bill, occupies the entire block south of the zócalo. Its architecture is a blend of severe Herreresque-Renaissance and early baroque styles. Construction began in 1550, but most of it took place under Bishop Juan de Palafox in the 1640s. At 69m, the towers are Mexico’s tallest. The dazzling interior, the frescoes and the elaborately decorated side chapels are awe-inspiring, and most have bilingual signs explaining their history and significance.