On August 5, 1934, German open-wheeler ace Rudi Caracciola lined his massive, 4.3-litre supercharged 332kW V8 Mercedes W25 up on the roadway outside Linthal, the cobblestones quaking with every throttle blip, before roaring away to conquer the Klausenpassrennen.
His time of 15m 22.2sec set an all-time record for the 21.6km journey, the longest hillclimb in the world.
It was the last time any competitive motorsport would be held on the Klausen Pass until 1993, when the authorities finally relented and a commemorative event held.
Amazingly, given the advent of modern technology over the ensuing six decades, no one but no one in the field of 450 drivers and riders could beat Caracciola’s time.
The significance of the moment is not lost on me, for our passage from St Moritz to Lake Luzern has been dutifully routed so that our comparatively diminutive RenaultSport Clio RS 220 Trophy might trace the lines of Caracciola’s mighty Silver Arrow all those years ago.
Klausen is the first ‘major’ alpine pass south of Zurich, a little more than an hour’s drive away.
Closed from November to June/July due to heavy snowfall, the summit can be reached from opposite directions — Linthal in the south and Altdorf to the north.
Opened in 1948, the road to the top is called Klausenstrasse.
Our adventure starts outside Linthal on the very same, hallowed cobblestones that underpinned Caracciola and rivals launch towards the summit, marked by a chalk line across the road with ‘Start’ scrawled on it.
Some 136 curves, including 35 hairpins, and a climb of 1237m later, there’s another line, annotated `Ziel’.
From cobblestone, the road quickly morphs into modern asphalt, winding up through forest and taking in several high-speed sweepers.
Then comes a series of tight switchbacks, a succession of short tunnels, another straight stretch and the forest thins out.
I’ve got the RS 220 dialled in accordingly.
Its peppy little 1.6-litre turbo four-pot is ever-ready to bring the sum of its 162kW and 280Nm (on over-boost) to the table.
The virtues of a compact wheelbase and track with grippy rubber at each of the four extremities are immediately obvious in the twisty going.
Any curve offering long and unobstructed line of sight can be taken kissing the inner and outer edges with nit-picking precision.
The car feels light, responsive and nimble and mid-corner grip and drive constantly impress; you can almost feel the car pre-loading its suspension and steering in anticipation.
Credit must go to the RS Drive switch, which modifies the mapping of the transmission (shift programming and paddle-shift time) and engine (throttle response and engine pitch), while at the same time weighting the steering and re-calibrating the extent and timing of the ESC/ASR intervention
As things level out, we suddenly burst into the open and on to a 5km-long alpine plateaux at Urnerboden.
It seems incredulous that here – on a bumpy surface now sign-posted 50km/h – the Silver Arrows of Caracciola and co. would have been in full cry at 250km/h all those years ago.
We appear to be heading towards a dead end, hemmed in by massive granite walls but, no, to the right the climb starts all over again, hewn into the mountainside.
Some 8.7km later, a pock-marked metal sign ‘Klausen Pass’ – and, less visible, the names ‘Rudi’ and ‘Tazio’ (Nuvolari) chalked onto the rock face – proclaims that we’ve reached the summit.
Time, now, to stop and syphon off the overflow of adrenalin into the catch tank.
We grab a coffee, check out the souvenir shop, the tiny, historic chapel alongside and what is some serious, high-performance machinery parked up.
It’s a wise thing to reset, because the drive down the other side is best made with your eyes out on stalks and foot covering the brake pedal.
For here, the road not only clings narrowly to the mountainside, but there is an absence of guard rail, just tube fencing that would not restrain even the lightest and slightest of four or two-wheels from plunging over the sheer drop-offs.
Absolute on the edge stuff; literally.
Further down, though, beast gives way to beauty.
A waterfall plunges several hundred metres into the valley, the road broadens and swoops and we drop into Alpine forest.
The descent ultimately finishes at Burglen, from where folk hero William Tell hailed, and there’s a museum dedicated to his legacy.