Monasterio de Santa Catalina
Even if you’ve already overdosed on colonial edifices, this convent shouldn’t be missed. Occupying a whole block and guarded by imposing high walls, it is one of the most fascinating religious buildings in Peru. Nor is it just a religious building – the 20,000-sq-meter complex is almost a citadel within the city. It was founded in 1580 by a rich widow, Doña María de Guzmán.