La Cumbre is the top of the world's most famous bad road. At about 4,650 metres, on a windswept pass in the Cordillera Real a short ride from La Paz, the tarmac gives way to the old North Yungas Road, which drops from this bare, cold, grey landscape to the steamy green jungle valleys about three and a half thousand metres below. The air is thin enough that a short walk from the bike leaves you breathless, and small roadside shrines hold the offerings that drivers leave for a safe descent.
The road down is the Camino de la Muerte, the Death Road, so named by the Inter-American Development Bank in the 1990s, when it was described as the most dangerous road in the world. The old track, carved into the cliff by Paraguayan prisoners of war in the 1930s, was only a few metres wide, with a drop of hundreds of metres on one side, and by most accounts hundreds of people died every year in crashes. A modern highway opened in 2006 and took most of the traffic, and the old road is now used mainly by cyclists, riders and tour groups. It is still a narrow, gravelled, rutted road with no barriers, and drivers keep to the left so that the driver can see the edge.
For a motorcyclist, the descent is an adventure that demands respect. The gravel is loose, the drops are real, and waterfalls splash across the road in places, making patches of mud. Fog and rain are common and visibility can disappear in seconds. There is a small fee to ride the old road, collected at a checkpoint. Many riders choose to hire a local guide on the first descent, and it is wise to avoid the afternoon when mist comes in, and to give the groups of cyclists plenty of room.
The altitude is a serious matter. La Paz sits at about 3,600 metres and El Alto above it at 4,000, and the ride to La Cumbre adds more. Altitude sickness is real, so spend a day or two acclimatising, drink water, and take it easy. Bikes lose power in thin air and carburetted engines can run rich. The cold and the wind are formidable, and snow is possible even in the dry season, from May to October, which is the best time to ride.
Fuel and services are in La Paz, about twenty-two kilometres away, and there is nothing at the pass. Fill the tank before you leave, bring water and warm gear, and keep an eye on the weather.