The Grimsel is a road made of granite. At 2,164 metres, the pass sits at the junction of the Bernese Alps and the Valais, in a bare, polished landscape of rounded boulders, tiny lakes and big reservoirs, where the ice of the last glaciation scraped the rock smooth. There is almost nothing growing at the top, and the sky seems close enough to touch.
The road is a classic. Coming from Innertkirchen on the Bernese side, it climbs the Haslital in long straights and hairpins, passes the dam of the Räterichsbodensee, and then reaches the summit with a lake on each side. On the south side it drops in a series of tight hairpins to Gletsch, with the Rhône glacier appearing ahead. The surface is good, the corners are well signed, and the views are huge. It is also very popular, so expect cars, buses and other bikes on fine summer weekends. Start early, and you will have the best of it.
The pass has been used since the Middle Ages by traders and pilgrims, and a hospice on the summit has sheltered travellers for centuries. Much of the surrounding country is part of a huge hydroelectric system, with tunnels and power stations buried in the mountain, and the water that powers it is the melt of the surrounding ice. Alpine choughs wheel on the thermals, and marmots whistle from the grass on the lower slopes.
The pass is closed in winter, usually from about November to late May, depending on snow. A cafe and restaurant at the hospiz offer coffee, soup and cake, with high prices that you will forgive when you see the view. It can be cold and windy, even in July, so keep a layer in the top box.