Reserva de la Biosfera Tehuacán-Cuicatlán

A UNESCO World Heritage Site in Puebla and Oaxaca that protects the world's most diverse assemblage of columnar cacti — 81 species including the cardon, which grows to 15 metres — in a Sonoran-Chihuahuan transitional desert ecosystem. The reserve also protects the earliest evidence of the domestication of maize, squash, and chiles by pre-agricultural Mexican peoples.