Housed in the former Dominican convent of Santo Domingo, the museum of Oaxacan cultures offers a glimpse at the state's history from ancient times through the colonial period, and into the modern day. The building was beautifully restored and opened to the public in 1998. You should go in even if just to see the interior of this stunning building, but the exhibits are also excellent. The highlight of this museum is the Treasure of Tomb 7, an offering that was found in a tomb at Monte Alban archaeological site. This is the greatest treasure ever found in Mesoamerica, and contains exquisitely crafted gold jewelry, as well as precious stone, intricately carved bone and more.