Oaxaca mermerize me because of its great churches. The catedral, with the tipical sismic key, the square facade and its baroche ornamentation. The Santo Domingo church is an amazing building because of its size and exquisite decoration. It does not have a great "chapel of the holly rosary" as many Dominican's churches. and of course the culture made the town a great experience. What surprise me, was how close is from Monte Alban, wich is another Unesco site.
The Valley of Oaxaca is full of fantastic sites. The open roof church and convent (Dominicans) and Mitla, another Zapotecas site, plus the cementeries made the area an Unesco destination.