The Eiger is 3,967 m (13,015 ft), in the Bernese Oberland of Switzerland, southwest of Grindelwald. It forms a famous trio with its neighbours the Moench and the Jungfrau. By Alpine standards it is not tall: the range’s 4,000-metre giants are all higher. The Eiger’s fame comes from its north wall, not its altitude.

Because of its North Face, the Eigerwand, a 1,800-metre wall that is the most storied and feared in mountaineering. Through the 1930s a string of climbers died trying to force it, watched by spectators and the press from the valley at Kleine Scheidegg, until a four-man team finally climbed it in 1938. It is one of the three great north faces of the Alps, alongside the Matterhorn and the Grandes Jorasses.

Mordwand means murder wall in German, a grim play on Nordwand, the north wall. The nickname stuck during the deadly attempts of the 1930s, when the media cast the face as a suicide mission. At least 64 climbers have died on the North Face since 1935. The name endures, though modern climbers approach the wall with far better equipment, forecasting, and technique.

On 24 July 1938, after a three-day climb, Anderl Heckmair, Heinrich Harrer, Ludwig Voerg, and Fritz Kasparek reached the summit by the North Face. Two roped parties, one Austrian and one German, joined forces on the wall. Their line, the Heckmair route, remains the classic and most-climbed way up the face. Heinrich Harrer later wrote a famous account of the wall, The White Spider.

They are two very different climbs on the same mountain. The West Flank is the normal route, a serious but far less technical snow and scramble line that is also the standard descent, and the way most climbers reach the summit. The North Face is the Heckmair route, an elite ED2 alpine climb of 1,800 m. Most people who stand on the Eiger’s summit never touch the face.

It is one of the most dangerous classic climbs in the Alps. At least 64 climbers have died on it since 1935, from rockfall, ice fall, avalanches, and sudden storms that can trap a party high on the wall. Rockfall is the defining hazard, which is why the face is usually climbed in cold, frozen conditions. It should be attempted only by very experienced alpinists, ideally with a guide who knows the wall.

The standing solo record on the Heckmair route is 2 hours 22 minutes 50 seconds, set by the Swiss alpinist Ueli Steck on 16 November 2015, on a wall that took its first-ascent team three days. Dani Arnold soloed it in 2 hours 28 minutes in 2011. These are extraordinary feats by the world’s leading alpinists; a typical fast, competent party takes something more like 10 to 20 hours.

The North Face is usually climbed in cold conditions, often late winter and early spring, when the wall is frozen and rockfall is reduced; summer ascents face more loose rock. The West Flank and the Mittellegi Ridge are summer objectives. In every season the Eiger is a conditions game, and settled cold weather matters more than the calendar.

It depends entirely on the route. The North Face demands elite mixed-climbing skill, speed, and conditions judgment, well beyond a first serious alpine climb, and even strong alpinists hire a guide. The West Flank and the Mittellegi Ridge are real mountaineering routes that still require solid alpine skills, fitness, and a guide for most climbers. None of the routes is a walk-up.