We walked one such in January (2017) in Switzerland: the Gemmi Pass, which links the Swiss capital Bern (and a lot of western Switzerland) with the Rhone valley. You can walk all the way, up from Kandersteg, at the northern (Bern) end, across the top and then down to Leukerbad in the south, and we did that in our younger days, but this time we were staying in Kandersteg, so tool the cable car up and down, and walked along the trail between the peaks of the Rinderhorn (3448m) and the Daubenhorn (2942m) to the high point of the pass above Leukerbad, and then turned round and walked back.
Much of the route is flat(tish) across a broad valley, and alongside a lake called the Daubensee. It looks as though geography would have determined the course from ancient times, but research shows that at the southern end, the original route (the Alte Gemmi) ran to the east of the present one, and was several hundred metres higher. There is evidence that some travellers used this route from the 9th century CE, with a hostel or refuge in place from the 12th or 13th century. By the 18th century, more people were wanting to visit the spa at Leukerbad, so a path was built into the mountainside to take the route over a lower point in the mountain range, which has been used ever since.
The pass is a frontier in more ways than one. It marks the boundary between the Swiss cantons of Bern and Wallis (Valais in French) – see the pictures of the boundary stone and flags on a nearby rock.
It’s a linguistic frontier between the French-speaking Valais and the German-speaking Bern. And geographically, the pass marks the end of the Bernese Oberland, and the mountains in the fantastic view looking south are the Valais Alps: the best-known is the Matterhorn, though the Weisshorn and Dom are actually higher.
One other building linked to the route is the Ruedihus, now a restaurant on the outskirts of Kandersteg, which was built in 1753, and served, among other things, as a staging post for travellers over the Gemmi pass where they could change mules (rather than horses) and no doubt refresh themselves before or after a tricky section of their journey. We enjoyed an unusual white wine soup, as well as the history – Swiss Parliamentary retreats have taken place there.
Some well-known people have travelled across the Gemmi pass. Mark Twain wrote about it in “A Tramp Abroad”. He admired the Alpine flowers on the way up, but near the top found “a storm-swept and smileless desolation. All about us rose gigantic masses, crags, and ramparts of bare and dreary rock, with not a vestige or semblance of plant of tree or flower anywhere, or glimpse of any creature that had life”. Twain did however develop an interest in mountain climbing there, and went on an expedition from Zermatt. (Thanks to Project Gutenberg for making the text easily available, http://www.gutenberg.org/files/119/119-h/119-h.htm#ch35.)
Other walkers across the Gemmi include Alexandre Dumas, Jules Verne, and Guy de Maupassant (who mentioned it in a story called “The Inn”), all of whom signed the visitor book at the Hotel Schwarenbach, which is about halfway across the pass, along with Lenin and Picasso to break up the literary fraternity. Sir Arthur Conan Doyle took Sherlock Holmes and Dr Watson over the pass on their way to his (at the time) death at the Reichenbach Falls.
These days, the Gemmi pass is the province of walkers, and in winter, cross-country skiers, para-skiers, and others. There is an alternative to get to the central Rhone valley from the Bernese Oberland: you put your car on the train in Kandersteg, and emerge the other side. It’s quicker, of course, but you won’t get the joy of seeing the new mountain range emerge ahead of you, and the sense of travelling a route carved out hundreds of years ago.