Nature Reserve
Reserva de la Biósfera Santuario Mariposa Monarca
In the eastern-most corner of Michoacán, straddling the border of México state, lies the incredible 563-sq-km Monarch Butterfly Biosphere Reserve, a Unesco World Heritage site since 2008. Every autumn, from late October to early November, millions of monarch butterflies begin to flock to these forested Mexican highlands for their winter hibernation, having flown all the way from the Great Lakes region of the US and Canada, some 4500km away. The butterflies arrive in waves, the last remaining until early to mid-March, when they begin their return journey north.