Las Derrumbadas

Las Derrumbadas are twin rhyolite volcanic domes in eastern Puebla, shared by the municipalities of Guadalupe Victoria and San Nicolás Buenos Aires. Officially both are called Cerro Derrumbadas; locals call the southern summit (3,480 m) the Derrumbada Roja or de Fuego, the Red or Fire one, and the northern summit (3,420 m) the Derrumbada Azul or de Agua, the Blue or Water one. A third hill a few kilometres north, Cerro Pinto or the Derrumbada Blanca (about 3,000 m), is sometimes counted too. Both main summits rank among Mexico's 30 highest peaks, even though neighbours such as Cofre de Perote, Sierra Negra and Pico de Orizaba overshadow them.

They rise from the Llanos de San Juan, a closed, semi-arid basin of the Trans-Mexican Volcanic Belt, close to the salt lakes of Totolcingo and El Salado and the crater lakes of Atexcac, Alchichica, Las Minas and Quechulac. Federal highway 140 skirts the north-west side of the Blue dome. The volcanoes still have fumaroles, especially the Red one, and have been studied as a source of geothermal power. Their rhyolite is a valued building stone, and several companies quarry it at the foot of the hills.

The sunny slopes carry dry scrub with agaves and succulents, giving way higher up to pine-oak forest and, on the highest shaded faces, sacred fir. They are little known as a destination, but hiking clubs such as CEMAC run regular ascents. The climb is tricky: the ground is loose and prone to rockfalls, which is where the name, "the collapsed ones", comes from.