Sierra Negra (Cerro La Negra) is an extinct volcano at an elevation of 4.576m (15,013ft) above the sea level located in the Mexican state of Puebla. It’s one of the highest roads of the country.
Set high in the highlands of south-central Mexico, the road to the summit, also known as Tliltépetl or volcán Atlitzin, is totally unpaved and very rough in many places. A 4x4vehicle is required. The road is very curvy and winding. It’s one of the most hairpinned roads in the world. The summit hosts the Large Millimeter Telescope, the world´s largest single-dish steerable millimetre-wavelength telescope designed specifically for astronomical observations in the wavelength range of 0.85 – 4mm.
Located within the Pico de Orizaba National Park, the road to the summit is very steep, hitting a 17% of maximum gradient through some of the ramps. Starting at Atzitzintla, the ascent is 18.5 km (11.49 miles) long. Over this distance the elevation gain is 1.849 meters. The average gradient is 9.99%.
Close to the border with Veracruz state, remember this is a mountainous area, climbing up a high mountain, with a notorius absence of oxygen. Altitude and extreme weather are always a factor. It’s one of the highest roads of North America. The road up to Sierra Negra's summit is closed to private vehicles, one needs special permission to use it
Pic: jean gamboa