La Cumbre is the high point of the North Yungas Road, a pass at roughly 4,650 metres above sea level where the road tips over the rim of the altiplano and heads down into the cloud forest. The setting is stark: cold, bare, boulder-strewn slopes with patches of snow, a few shrines and a statue of the Virgin, and a lot of wind. On a clear day the snow peaks of the Cordillera Real line up to the north, and the contrast with the green world below is almost theatrical.
There are no services at the pass itself, and La Paz is about twenty-two kilometres back, so make sure the tank is comfortable. The temperature can be near freezing even in the dry season, and fog and sleet are common. Many riders stop here for a moment to rest, add a layer for the descent, and take a photograph at the sign. Breathe slowly, because at this height even small efforts leave you winded, and be ready for a headache.
The old road, famous as the most dangerous in the world, starts a little below and was built in the 1930s, partly by Paraguayan prisoners of war captured during the Chaco War. Narrow, unpaved and bordered by drops of hundreds of metres, it claimed many lives in its heyday, and crosses in places mark where vehicles went over. A new paved highway now carries most traffic, so the old route is used mainly by cyclists and adventurous riders.
If you choose it, expect a steep, loose, wet and sometimes foggy gravel road with waterfalls pouring across the track. Drive on the left of the road, as local custom has it, so the driver can see the edge. Take it slowly, avoid riding in rain if you can, and carry water, tools and a spare tube. If you take the paved road instead, you still get dramatic views and a spectacular descent through cloud. Either way, this is one of the wonders of the continent.