Depart Leymebamba and quickly arrive at the tours joint highest point, 3,600m, before decending to 850m and back up again, at least twice!

The cloud at 3,600m is so thick the valley below disappears, hiding the full terror of the potential drop-off. Looking out of the other side of the van at the damp rock face sees every surface and crevice covered with lichen, algae, ferns and bromeliads living on the moisture filled air and any thin layer of soil clinging to the rock.

After 300m of descent the cloud clears, the ambient temperature rises and the flora changes to shrubs, trees and grasses, passing through pampas down to fruiting mango trees at the bottom of the fertile Marranon valley at 850m altitude in moist heat.

Crossing the Rio Marranon, and ascending up through baking heat everything changes abruptly again - thus time it's high noon in dry gulch from the western's of my (parent's) youth - dusty comic book cacti and leafless, twisted trees simply aching to burst into life at the first hint of moisture stud the desert landscape.

Not that Hegel, our driver, has the chance to take in the changes - his eyes are glued to the now rising road. During the 60 km of road and 3 km of descent, we met only 1 motorbike and 1 car coming up. All this changes on the ascent with a steam of bikes, cars, vans and lorries coming down as we climb.

Peruvian mountain road etiquette dictates that size matters, or the climbing vehicle has right of way, or the most bloody minded driver wins ... It's a lottery basically, conducted via blasting horn salvos with a a bent fender or worse awaiting the first false move. Hegel only once bids my wind down the window and check how close his off-side front wheel is to the edge, but that's plenty enough for me.

After 10 hours' driving we reach Cajamarca to find there is no reservation for us - the receptionists repeated demands for a wowcher gave us the clue and all the doubles are fully booked. Luckily for all concerned they have a single and a triple, the single looking for all the world like the size of last nights double. Happiness all around!