Vying with the Ice Maiden Juanita as Arequipa's most famous attraction, Santa Catalina is one of the colonial architectural highlights not just of Arequipa or Peru, but South America as a whole. It's often described as a city within a city, and while this is a slight exaggeration (it occupies a full city block so "town" would be men appropriate), it's otherwise fully worthy of its considerable fame. The only disappointment is that its citadel (the only of its kind inside a convent in the world) doesn't offer a view of much beyond the convent, but I suppose that in itself is singularly appropriate.
The convent was founded in 1579 and was fully cloistered for the following 391 years. That means that the nuns, once they had entered and spent the obligatory year in the novice's area, couldn't leave - they could only speak to visitors through wooden grilles that resembles confessionals and are among the first things you see when you enter. You also encounter guides, whose services I did not personally employ but whom friend said were excellent. The novice's quarters follow after which various courtyards lead into a series of streets named after cities in Southern Spain. The nuns themselves had to be of pure Spanish blood (an unfortunately typical example of colonial racism) although they were often attended by slaves, an appalling concept to begin with, but even more so since they'd nominally moved to the convent to participate in an austere religious life.
Some sources I've read (not the convent's own materials) have indicated that the life they lived was far from austere and contemplative, although unusually the nuns had a great degree of autonomy in running their own affairs without interference from the local bishop. Depending on whether you believe the convent's materials or those of its critics, he subsequently stepped in either to assert greater episcopal control or to rein in the nuns' sybartic behavior. In 1970, the convent became half-cloistered (meaning the nuns could leave and receive visitors) adn the nuns moved to a modern building, leaving the historic convent as a tourist attraction. Admission fees now support the convent, which in a prior era relied on the "dowries" brought by nuns who joined the convent.
While helpful, none of this history (which is contained in helpful wall plaques) is necessary to appreciate the convent's subtle and someone sensuous delights. It has the general feeling of an immaculately preserved deserted village in Southern Spain, complete with streets, houses, fountain, orchard, and church. This sense is enhanced on Tuesdays and Thursdays (when it remains open until 8 pm instead of the usual 5 pm) when the fires of its kitchens and the candles along its walls are lit. The best time to visit is in the afternoon, when the changing angles of the sun turn its blue and ochre painted walls a variety of subtle hues that seem to encourage contemplation. I think this feeling is entirely consistent with the convent's spiritual and contemplative message - I left with the feeling that its simplicity was its beauty and vice versa.