The Museo de Grana Cochinilla focuses on one of Oaxaca's strangest and most important historic products: cochineal, the red dye made from insects cultivated on prickly pear cactus. For centuries it was a valuable export, colouring textiles, manuscripts, and luxury goods far beyond Mexico.
The museum is small, but the subject is excellent if you care about craft, trade, or the hidden materials behind colonial wealth. It pairs naturally with Oaxaca's textile villages and markets, where colour is still one of the region's great pleasures.