Casa de Benito Juárez is the childhood home of Benito Juárez, the Zapotec lawyer who became one of Mexico's most important presidents. The house is plain, which is exactly the point: it makes his humble beginnings easier to imagine than a grand monument would.
It is a small stop, but a meaningful one if you are interested in Oaxaca's role in Mexican history. Visit it with the nearby Santo Domingo area and Oaxaca's central museums.