The path is steep and stony. It's blazing hot - every 20 minutes you stop and slather on more factor 50. You've been going an hour and two-thirds of the water's been drunk.
It's also rather dangerous. Unbeknownst to you, when you were stuffing your daughter's jacket into your rucksack, wife and child have taken 'what looked like a shortcut' - concentrating on fitting everything back into the bag, you blindly follow, not noticing that the main path goes up and to the left. You're now close to the edge of a big drop and the path seems a lot smaller than it was.
Ten minutes later ...
"I can't believe the authorities signpost this path as a suitable route. You'd never be allowed to do that in England. Do people really take small children up here ?"
Fifteen minutes later ... the path is between a foot and eighteen inches wide. We've climbed enough to make going back probably more hazardous than going on. To the right, at the edge of the path, a drop to the river several hundred feet below.
"Walk carefully - stay as close into the hill as you can. This is dangerous. They must be crazy to designate this as a route"
"I wonder if we should have gone left instead of straight on when the path split"
We had to keep going. About another half mile and maybe thirty minutes on, our tiny path zig-zagged up to join the broad main path, which we'd been following a couple of hundred feet lower down the ravine. We'd added a somewhat twitchy hour to the walk time. And I swore never again to just follow without keeping my eyes open.
Walking on, the ravine opens out - higher up you can fill your bottles with clear, cold river water.
And then you come to what seems like a mirage - an oasis for hot, sweaty walkers, a dream of paradise, a beer advert come to life.
There's a fountain of cool drinking water, shady trees about a river, a small bridge. And about six bars and restaurants! Bulnes was presumably once a very cut-off village - but a funicular railway cut through the mountain (and free to locals) now means that all the wants of the climber or tourist can be brought up.
After a walk like ours, to sit under a sunshade and sip a chilled beer feels very good. And the descent is a great improvement on the ascent - even the heat's less, with the ravine now in shadow. Lovely place - I can see why people rave about the Picos de Europa. Will come again.