Each winter more than 150 million monarch butterflies migrate from the northeastern US and Canada to the Oyamel fir forests in the lush mountains of Michoacán in order to reproduce. It’s an amazing sight at any time, but especially in January and February when numbers peak: whole trees are smothered in monarchs, branches sagging under the weight. In the cool of the morning, they dry their wings, turning the entire landscape a rich, velvety orange, while later in the day they take to the air, millions of fluttering butterflies making more noise than you’d ever think possible. As the afternoon humidity forces them to the ground, they form a thick carpet of blazing colour. The place to see the monarchs is in the Santuario de la Mariposa Monarca about 120km east of Morelia, with entrances at El Rosario and Sierra Chincua, near the village of Angangueo. While the Sierra Chincua entrance is, on the face of it, less convenient, with public transport dropping you 2km short, the hike inside the sanctuary is actually less strenuous from here. There are also sections of the sanctuary across the state line in the State of Mexico, which are most easily visited from Valle de Bravo, but can also be accessed from Zitácuaro.