Spitallamm, Canyon in Grimsel region, Switzerland

Spitallamm is a gorge on the upper Aare in the Bernese Alps, in the municipality of Guttannen. It is 200 metres deep and 300 metres wide, cut into crystalline rock of the Aarmassiv; the river once ran 500 metres through it. Above the left bank rises a glacier-rounded spur below the Juchlistock, opposite the Spittelnollen (1980 m).

Since the Middle Ages a mule track from Meiringen to the Grimsel Pass crossed the Aare here on a bridge. In the first half of the 19th century Bern rebuilt it as a road, which ran on the eastern bank and needed no bridge. From 1925 to 1932 the Kraftwerke Oberhasli built the 114-metre-high Spitallamm arch dam in the gorge, closing the Grimselsee reservoir together with the Seeuferegg dam.

The name Spittellamm comes from the old Alpine word Lammi or Lamm, meaning a rock cleft hollowed out and flowed through by water, related to the Bavarian Klamm. The first part refers to the Spittel, a hospice on the south side of the gorge that sheltered travellers between the Haslital and Valais; it later became known as the Grimselhospiz and now lies under the Grimselsee. The nearby Spittelnollen and names like Cheistenlamm and Lamma in Goms carry the same word.

The gorge lies on the Aare below the Spitallamm dam, on the road to the Grimsel Pass in the municipality of Guttannen. The old mule track crossed the river on a bridge here; the 19th-century road kept to the eastern bank and needed none. The deep gorge is best seen from the forecourt of the Hotel Grimsel-Hospiz on the Spittelnollen.

The 114-metre Spitallamm arch dam, built by Kraftwerke Oberhasli between 1925 and 1932, closes the Grimselsee reservoir together with the 42-metre Seeuferegg dam east of the Spittelnollen. Traces of the construction-site installations from those years can still be seen in the gorge, and the reservoir's bottom outlet discharges into the Aare below the wall.