Oaxaca is a wonderful destination, and the prettiest capital city in Mexico,
I think. The city itself is very interesting, and the two ruin areas outside
it (opposite directions, as I recall) are interesting and educational. You
want to book a tour there with a guide, as you will learn much more than
One ruin area is Monte Alban, dating to 600 BC; the other is Mitla, about an
hour from town and dating to the lst century BC.
The Saturday Indian Market in Oaxaca is great.